These words of homage to Professor Sergio Arturo Montero Alarcón (Figure 1) bring to mind many images of the multifaceted, prolific, and extensive career of the restorer born on August 7, 1937, in Mexico City and who died there on June 14, 2020, surrounded by his loving family: his wife, Dora Oropeza, and their children Irina, Yuri, and Iker.

What is most striking about Professor Montero is the deep sense of admiration for his career as a pioneer, founder and master builder of Restoration in Mexico, aspects that in themselves make the task of fairly describing his great leadership, impact, and influence in the spheres of cultures and heritage, as well as their conservation and their dissemination, very complex. It was, although, unquestionable and unavoidable, that this inaugural issue of the new era of Intervención published some words dedicated to the person who will continue to be not only one of the greats in the field of conservation-restoration in Latin America, with a career of more than 45 years at the Instituto Nacional de Antropología e Historia (INAH), but, above all, a leading authority in the academic field, since for four decades he was a distinguished, highly respected, and deeply loved teacher at INAH’s Escuela Nacional de Conservación, Restauración y Museografía (ENCRyM).

To begin with, it should be noted that the upbringing of Montero occurred in the bosom of a bicultural family, with an artistic streak and strong political convictions. His parents, Dolores Alarcón, a Mexican, and Marco Arturo Montero Valdés, of Mexican-Cuban origin, were trained at a Vasconcellian school. Montero Valdés was a poet and musician, to which he added a significant role as a leftist political activist and member of the Communist Party (CP). He was the founder of the Liga de Escritores y Artistas Revolucionarios (LEAR) (Montero, personal communication, 2020; ^{Méndez, 1981}). With this background, it is not surprising that the primary and secondary education of Sergio Montero took place in the state-run school system. The Mexican state-run school system underwent fundamental changes during the 1940s and 1950s thanks to its professionalization and national expansion, on the one hand, with the foundation and expansion of the Escuela Normal Superior, and, on the other, with the institutionalization of the teaching profession and the establishment of the National Education System, under the leadership of Jaime Torres Bodet (Ornelas, 1995). What is surprising is the interdisciplinary fabric that the higher education of Montero wove between the disciplines of applied science and art. In addition to undertaking vocational studies in engineering and architecture at the Instituto Politécnico Nacional (IPN), Montero graduated in 1958 from the Escuela Nacional de Pintura, Escultura y Grabado La Esmeralda at the Instituto Nacional de Bellas Artes y Literatura (INBAL). Montero thereby acquired a solid grounding in the creative and spatial areas of cultural assets, to which he would afterwards dedicate a significant part of his life as a restorer of easel paintings, murals, and sculptures (Montero, 2018). In particular, his time at La Esmeralda underpinned his interest, as he would declare years later, in the "technique of painting [... which] I liked very much; the preparation of materials, their content, and all that" ^{(Ventura, 2011, n.p)}.

Around the 1960s, the educational journey of Montero took an extraordinary turn toward international experience; a scholarship he acquired as part of the Young Communist Party allowed him to become a student of restoration of works of art and historical monuments at the Academy of Fine Arts and Design, Bratislava, Czechoslovakia (Montero 2018; Montero, personal communication, 2020). Few know that his area of educational specialization at that time was primarily sculpture (González, 2010). This transatlantic journey would make him the first Mexican restorer with specialized studies it would also define his approach to the discipline. As he said: "I learned the principles of restoration [in Europe] and applied them to solve the problems I had to face when I returned to Mexico" (González, 2010, p. 1).

Indeed, that was the case. On his return to Mexico in 1962, Montero, being one of the first restorers of modern Mexican art, innovated by undertaking the detachment, transfer, and treatment of murals by Cecil Crawford O’Gorman and Fermín Revueltas (Figure 2); work of the latter was initially located at Banco Azteca in Mexico City ^{(Ventura 2011)}.

One year later, in 1964, Montero joined the ranks of INAH with a double role as a restorer. On the one hand, as a member of the staff and head of restoration (1963-1982) of the recently created INAH’s Departamento de Catálogo y Restauración (DCR) -firstly based in Culhuacan and later in Churubusco-, he restored Pre-Colombian and Viceregal murals, as well as historical easel paintings, all under the direction of Manuel del Castillo Negrete (Figure 3). On the other hand, Montero also served as conservator of archaeological materials in the Department of Prehistory (1963-1964), located in the Historic Center of Mexico City. As head of restoration at the DCR, an institution that would become the current Coordinación Nacional de Conservación del Patrimonio Cultural (CNCPC), Montero participated in and coordinated the restoration of the monumental paintings of Cristobal de Villalpando and Miguel Cabrera, at the cloister of the Aljibes, and the sacristy of Tepotzotlan, respectively, as well as the mural paintings of the convent of Santo Domingo in Oaxaca. In the archaeological field, his work on the turquoise masks of Coixtlahuaca and Zaachila was especially noteworthy, and earned him the admiration of Ignacio Bernal (Montero, personal communication, 2018). These experiences boosted the exceptional and prolific career of Montero as a restorer and subsequently led him to a career in writing, first of all of reports, and later as a published author. He then penned several articles on restoration in the Boletín INAH, in which his skill in directly applying restoration criteria can be appreciated ^{(Montero 1964}, ¹⁹⁶⁵, ^1967a, ^1967b, ¹⁹⁷⁴⁾. The intervention of Montero on the masks of Coixtlahuaca and Zaachila is today a paradigm in the field of conservation-restoration of Mesoamerican turquoise musivary since it stands out for the application of applied science to the study of the materiality of these unique pre-Hispanic artifacts, as well as for the recovery of traditional indigenous technologies for conservation purposes. The resultant paper of this intervention ^{(Montero 1967a)} soon reached an international audience when translated into English for publication as the first collaboration of a Mexican in the already prestigious journal Studies in Conservation ^{(Montero, 1968)}. At the same time, as part of the teaching-learning process at the DCR, Montero began his role as trainer of technical restorers in mural painting.

In the mid-1960s, in the midst of strong national and international incentives that led to the establishment of UNESCO’s Centro Regional Latinoamericano de Estudios para la Conservación de Bienes Culturales (Cerlacor, the forerunner of present ENCRyM), Montero served as its founder, along with his lifelong friend Jaime Cama Villafranca. There he left a long-lasting and deep impression as a teacher of the first cohorts of Mexican and foreign restorers trained at Cerlacor, and in training courses in conservation and museology design sponsored by the Organization of American States (OAS).

With the inauguration of the ENCRyM, the academic career of Montero was consolidated for four decades as lecturer of diverse subjects and playing diverse roles in academic management, mainly in the bachelor’s degree on Restoration on Movable Heritage (LRBCM, acronym in Spanish). He instructed on the subjects of Introduction to the Technology of Cultural Property (1966-1977; 1983-1987), Restoration Techniques (1966-1977), Theory and Practice in Restoration Workshops (1966-1977), which later merged with that of the Technology and Restoration Workshop (1983-1987), Collection Management (1985-1989) and, importantly, the seminar-workshops of Introduction to Restoration (1989-1998) (now the Introductory Laboratory for the Restoration of Cultural Property, Labir, by its acronym in Spanish) and of Mural Work Restoration (1989-1998) (now known as the Seminar-Workshop of Mural Work Restoration (STROM, by its acronym in Spanish). In the latter, Montero shared the stage with teachers Haydeé Orea and Martha Tapia, professionals known today for their role in the training of restorers and the restoration of mural paintings in Mexico and Latin America. Also, during a brief period (1980-1983), Montero taught the Introduction to Restoration course for archaeology students at the Escuela Nacional de Antropología e Historia (ENAH).

In the mid-1980s, the director of ENCRyM, Jaime Cama Villafranca, proposed the restructuring of the academic program of the LRBCM, and to coordinate it he commissioned Montero, who eventually endorsed the concept of seminar-workshop as a transversal pedagogical space that actively builds interdisciplinarity through the interaction of knowledge derived from natural and human sciences (particularly anthropology), with a methodology of conservation-restoration. Undoubtedly, the notion-and organization-of seminar-workshops reflected not only the training of Montero but also the conceptual assumptions of prominent restoration theorists of the mid-20^th century, such as Cesare ^{Brandi (2000 [1964])}, Paul ^{Coremans (1969)}, and Paul ^{Phillipot (2000 [1972])}. Between 1983 and 1998, Montero was also an academic technical coordinator (1983-1992) at the ENCRyM, dean of its Academic Council (1993-1997), and a member of various academic commissions, including the University Degree Commission (1983-1992), and the Admissions Commission (1983-1998).

It should be noted that during the last decade of the 20^th century and the first decade of the 21^st century, following its innovation at the ENCRyM, the method of the seminar-workshop would be adopted by other higher education organizations in Mexico, to constitute one of the most precious and visible bastions of a Mexican school of conservation-restoration. This means that an overwhelming majority of restorers presently active in the INAH and other national institutions were, in one way or another, pupils of Montero.

It is interesting to note that, concerning his duties within ENCRyM’s admission process, Professor Montero left an indelible impression both for his presence-that of a fully-fledged professional restorer dealing with candidates for admission-and for setting in motion a series of activities aimed at valuing the collaborative and expressive abilities of the applicants, based on the transfer of skills from the practice of restoration and puppet theatre (Figure 4).

In sum, the academic career of Montero left, as outlined here, an imprint in various fields of academic management, pedagogical formulation, and teaching. A notable aspect of his educational career was his style of teaching, which was characterized by complementing technical explanations with biographical narratives. As Carolusa González Tirado pointed out, this method

…is a difficult teaching resource, which not everyone can use. To begin with, the teacher must have a large number and variety of important work experiences in his or her background, in order to choose, from this repertoire, the most appropriate one for each topic. Additionally, a certain attitude toward the group is required [...] anecdotes are needed that reflect significant challenges, problems that are almost impossible to solve, in order to capture the attention of students [... and to teach] what the real work of a restorer is, how a professional uses the data they know, evaluates situations, and makes decisions (González, 2010, p. 2, editorial translation).

Indeed, the teaching narrative of Montero taught the professional work of restoration and, indirectly, transmitted experience, gave an example of the magnitude of the work, explained how to practice the profession, and served as an example of how to be a restorer. In Montero, the relationship between practice and professional training crystallized into a very fine product; he advised and directed, among others, theses on easel painting (1990), mural painting, pre-Hispanic and viceregal stucco reliefs (1993-1994, 1998), and archaeological metals (1994). This connection also made it possible for him to be an advisor to many colleagues and directives of the INAH throughout his life.

As must by now be evident, the teaching legacy of Sergio Montero is incomparable. In real terms, it translates into the college education of dozens of generations of restorers and museum specialists of the ENCRyM, who today recognize him as a decisive pillar of their training because of his always generous lectures, personal qualities, and advice in theses. The community owes him its gratitude for his rigorous teaching style in which the professor directly displayed his observations, opinions, and methods-all of which are reasons to admire him-and, as previously pointed out, for the frequent anecdotes in which direct dialogue, his strong opinions, and his sense of humor prevailed. After his death, dozens of recollections and reflections were posted on a Facebook page called Para el Profesor Montero, which not only serve as witnesses to the positive effect of his work as an educator but also reveal, through a wealth of photographic images, the close relationships that he established with the students both in the classrooms of the ENCRyM and in various visits to heritage sites, in many of which he had carried out restoration work (Figure 5).

Furthermore, Professor Montero demonstrated his mastery in many settings. He participated in various educational initiatives in the field of conservation and museology in alliance with the Universidad Nacional Autónoma de México (UNAM, 1988), Universidad Autónoma Metropolitana (UAM, 1989-1992), and Instituto Mexiquense de Cultura (IMC, 1990). For more than forty-five years, he gave dozens of lectures and at national and international academic events organized by the ENCRyM, various agencies of the INAH, the ECRO, the INBA, the UNAM, the Sociedad Mexicana de Antropología de México (SMA), the Centro Cultural España (CCE MEXICO), the International Congress of Americanists (ICA), the Instituto de Antropología e Historia de Guatemala, the American Institute of Conservation (AIC), the Getty Conservation Institute (GCI), the International Council of Museums (ICOM), and various civil organizations. The teachings of Montero, therefore, impacted innumerable Mexican and foreign professionals who owe him their training in the heritage sector.

It is important to emphasize that Montero did not conceive all these efforts as isolated enterprises, but as mechanisms to consolidate the professional practice of restoration on a disciplinary and institutional scales, whose tangible results owe much to his tireless work. As previously mentioned, Montero was the organizer and coordinator (1963-1977) of the DCR restoration workshops, which today continue to shape the work of the CNCPC. Later, he would become deputy chief of restoration at the DCR, and between 1977 and 1982, in what he would call his period of exile from Churubusco, he served as the chief restorer of the INAH Hidalgo Center. In this way, he sought to decentralize his knowledge of professional and institutional procedures.

Moreover, the career of Montero as a director, executor, and project advisor is astonishing, making it seem impossible to summarize his entire career in a short text. Consequently, I will mention only some of the conservation-restoration initiatives that Montero recalled in recent years, with particular affection, as the prelude to an Anthology which, with his full collaboration in recent years, is being prepared for publication by the ENCRyM.

Sergio Montero was one of the first restorers of paleontological heritage: his work on the skeleton of a mammoth still resonates in the institutional memory. Likewise, he was a pioneer in the conservation of pre-Hispanic heritage: works that stand out, in addition to the abovementioned restoration of the turquoise mosaic masks of Coixtlahuaca and Zaachila in 1966 ^{(Montero 1967b} and ¹⁹⁶⁸⁾, are the conservation of an Aztec shrine from the Mexico City subway excavations in 1968 ^{(Montero 1972)}; the prodigious and avant-garde procedures, through the use of polymer resins, for the conservation of the monumental clay sculpture called Mictlantecuhtli in the archaeological zone of Zapotal, Veracruz (1972) (Figure 6); and the restoration of the mural paintings in the archaeological zone of Las Higueras, Veracruz (1967-1973), where he accomplished the task of detaching more than nineteen layers of Totonac painting from approximately 200 fragments (see González, 2010) (Figure 7).

It is also worth recalling the participation of Montero in the project for the restoration of the mural paintings in the archaeological zone of Cacaxtla, Puebla (1975) (Figure 8), as well as the maintenance, removal, assembly, and restoration of mural paintings from the archaeological zone of Teotihuacan, State of Mexico (1966-1977), including the objects resulting from the repatriation of the Wagner Collection (1984-1991).

Also noteworthy are his involvement in designing and making packaging for the Ocelotl Cuauhxicalli (Figures 9 and 10), exhibited in Washington (1983), and the Olmec head for the exhibition in Tokyo (1985).

In the archaeological zone of Bonampak, Chiapas, Montero participated in the preparatory studies for the restoration of the paintings of Building 1 (1967-1977, Montero 1985) and, of course, directed the majestic restoration of Stele 1 (Figures 11 and 12), work carried out in extreme conditions of isolation thanks to the precise coordination of a group of field technicians and the use of traditional lifting techniques (Montero 1977, 1994).

From his more mature period, it is important to denote the restoration of the Venus monolith of the archaeological zone of Tamtoc (2006), his collaboration for the replacement of the Tlaltecuhtli monolith of the archaeological zone of the Templo Mayor (2007), and the coordination for the packing and shipping of Mayan sculptures in the Canton Museum (2012) stand out (Figure 13).

His restoration work in historical heritage, although less known, is also worthy of recognition (Figure 14). It is laudable remembering the restorations of the monumental paintings of Villalpando and Cabrera de Tepotzotlán (1964) and of Rodríguez Juárez in the Metropolitan Cathedral (1967), and the mural paintings of Santo Domingo, Oaxaca (1964-1965), which were mentioned above.

However, one of his most significant and admired achievements would be the restoration, in two stages, of the mural paintings in the Casa de La Moreña, municipality of La Barca, Jalisco (1974-1977, 2007-2010). This represented a unique opportunity to evaluate both the performance of restoration materials in real conditions and times and the restoration decision-making process as a whole ^{(Montero 1991}; ^{Montero and Alfaro 2013)} (Figures 15 and 16).

Montero was also an innovator in the restoration of modern artworks by artists such as Cecil Crawford O’Gorman (1962), Fermín Revueltas (1962), Carlos Mérida (1977-1978), and Joaquín Torres García (2001). A fervent student and admirer of Mexican muralism, Montero was the director of the restoration project of the murals at the David Alfaro Siqueiros Polyforum (1994-1995) and acted as an advisor on initiatives presented in recent years on this vital part of Mexican heritage (cf. ^{Montero and Ramírez, 2000b}) (Figure 17).

The expertise of Montero extended beyond the borders of Mexico through multiple international commissions in Guatemala, Uruguay, El Salvador, the United States, and places as far away as Ethiopia and Japan (see ^{Montero, 2008}), as well as his cooperation with the Ministry of Foreign Affairs in educational matters (1991-1993). His advice in this area covered not only the restoration of mural paintings-particularly detachment and transfering of pictorial layers-but also preventive and post-disaster conservation, as well as the management of monumental works in international exhibitions. These commissions, which ran from 1973 to 2006, included Historic Routes (Ethiopia, 1973); mural paintings and decorations (Antigua Guatemala, 1973; El Salvador, 1994; Uruguay, 1997); and acting as courrier (Aztec art and Olmec art exhibitions, National Gallery of Washington, 1983 and 1996 respectively, as well as Olmec art, Osaka and Omiya 1986).

The versatility of the professional practice of Montero is outstanding, not only because it seems to go against the trend of professional specialization in the second part of the 20^th century, but also because of its innovative role in the gestation and performance of an integral vision of the ENCRyM, which has proven its effectiveness in the professional practice of its graduates, particularly in diagnostic work in the wake of disasters, carried out, among other times, after the earthquakes of 1985 and 2017. This was not by chance since Montero had ample experience as coordinator of the team of restorers for inspection and emergency procedures in the disaster zone in Puebla and Tlaxcala after the 1973 earthquake.

Heir to the social activism movements of the early 20^th century, Montero forged his path of collective organization in his discipline as an associate member of the International Institute of Conservation (IIC) and the Asociación Mexicana de Conservadores del Patrimonio Cultural, A. C. Montero was the founder of the Sociedad de Conservadores del Patrimonio Cultural, A. C. (Somecopac). Furthermore, in 2008, he was nominated as an advisor to the International Centre for the Study of the Preservation and Restoration of Cultural Property (ICCROM) Board of Directors, representing Mexico.

Fortunately, Montero was recognized during his lifetime with the Ignacio Ramírez merit award (Secretaría de Educación Pública [SEP], 1993) and by the Consejo Nacional para la Cultura y las Artes (Conaculta, 1995); with tributes at Somecopac (1995), at ECRO (2004), at CNCPC (2004); and on his retirement, he was recognized as an INAH expert restorer and teacher at the ENCRyM (2010) (Figure 18) .

Montero was also awarded the Puppetry Merit Award (Museum of Huamantla 2012). This last award was the fruit of his childhood practice of puppetry, which, as an adult, would lead him to found the Ikerin Theater Company. This hobby was strengthened with his work as a restorer, through the conservation projects of the Rosete Aranda Collection of the Rafael Coronel Museum and the Golden Age of the INBAL puppet theater (1983, 1990, 2007-2008, 2014; Montero 1995, 2012, 2014). These experiences led him to suggest a modification to restoration practices, as he himself pointed out: "I am certain that the puppets inside a showcase are no longer puppets. They have to be returned to their original function; otherwise, they are not puppets" (Cid de Leon 2009. In ^{Garduño, 2010, p. 40}, editorial translation). This wisdom was applied through his puppet restoration work and had consequences for the proposal of utilitarian and performative criteria for other cultural goods, including those belonging to musical and mechanical heritage (see ENCRyM-INAH, STOCRIM, 2013; ^{Medina-González, 2019}) (Figures 19 and 20).

The legacy of Montero is not only extensive but also complex. It is hard to begin to understand such a distinguished, multifaceted figure, a protagonist of the history of the restoration of Mexico, and a fighter for and promoter of the recognition of this discipline in Latin America. More than 30 publications, dozens of classes, conferences, and videos-some of which can be consulted on the INAH channel-on restoration work on cultural assets, history of the ENCRyM, and training in restoration remain as his material legacy. Of this wealth of information, the literature he left on technology, conservation-restoration, and detachment of mural painting stands out ^{(Montero 1967a}, ¹⁹⁷⁴, ¹⁹⁸⁶⁾. It is also worth mentioning the publication of multiple writings on the field, little recognized until today, of the design and manufacture of packaging for the transfer of works ^{(Montero, 1989}, ¹⁹⁹⁰, ^1991a, ^1991b). Likewise, the contribution of Montero to the development of preventive conservation guides, among the first of its kind in Mexico, is noteworthy ⁽¹⁹⁹⁵, ^1991b). There is also the published version of an anecdote about the airplane accident he suffered in Bonampak in the 1960s ^{(Montero, 2000)}, the winning text of the contest entitled Aquí les vengo a contar..., on the occasion of the 60^th anniversary of the INAH. However, what mainly remains are his restoration works and his teachings, all representative of his keen insight, his lively intelligence, and his brilliant capacity for theoretical, methodological, and practical discernment of restoration, on which he left many written reflections ^{(Montero 1980)}. His work as a restorer extended beyond his retirement in 2008, since this circumstance did not distance him completely from matters related to the discipline and the heritage of this country, to which he professed enormous devotion.

As noted above, upon news of his death, the responses in various electronic media were immediate, affectionate, and admiring. At the risk of omitting some details, the material legacy of Montero stands out, as well as his role as a pillar of restoration; a great teacher, since he taught how to be a restorer and how to practice the profession; his memory as a generous companion in activities that reflected the tenacity of his convictions; his rigorous approach; his kindly demeanor; and his very particular sense of humor. The editorial project of Intervención journal also owes gratitude to Montero, for having become the publication platform where his work, both technical and discursive, appeared most frequently in the last ten years of his life (^{Garduño, 2010}; ^{Montero et al., 2013}, ²⁰¹⁵, and ²⁰¹⁷; Vega 2019). Personally, I am grateful for all the teachings I received as a student and then as a professional. Our conversations in the hallway and the cafeteria provided wise advice and made me understand the responsibility involved in our work, marvel at the solutions that he encountered on various occasions, and value the development of the professionalization of the discipline of restoration, a unique Mexican project in the world that he, along with other greats, proudly forged in the heart of the INAH. I am left with all his teachings, which I will continue to remember, and in particular, a warning about the work of restoration that he often repeated with a confident smile: “He who knows nothing, fears nothing.” He knew and hinted at the depth of this phrase. Because of this, and because of what has been said above and much more that has yet to be reflected upon, we will miss you, and will always be with us, our dear professor.