Eugène Viollet - le - Duc Eugène Emmanuel Viollet - le - Duc ( 27 January 1814 – 17 September 1879 ) was a French architect and theorist , famous for his interpretive " restorations " of medieval buildings . Born in Paris , he was a major Gothic Revival architect . He was the architect hired to design the internal structure of the Statue of Liberty . Early years . Viollet - le - Duc ' s father was a civil servant living in Paris who collected books ; his mother ' s Friday salons were attended by Stendhal and Sainte - Beuve . His mother ' s brother , Étienne - Jean Delécluze , " a painter in the mornings , a scholar in the evenings " ( Summerson ) , was largely in charge of the young man ' s education . Viollet - le - Duc was trendy philosophically : republican , anti - clerical , rebellious , he built a barricade in the July Revolution of 1830 and refused to enter the École des Beaux - Arts . Instead he opted in favor of direct practical experience in the architectural offices of Jacques - Marie Huvé and Achille - François - René Leclère . Architectural restorer . Restoration work . During the early 1830s , a popular sentiment for the restoration of medieval buildings developed in France . Viollet - le - Duc , returning during 1835 from study in Italy , was commissioned by Prosper Mérimée to restore the Romanesque abbey of Vézelay . This work was the first of a long series of restorations ; Viollet - le - Duc ' s restorations at Notre Dame de Paris brought him national attention . His other main works include Mont Saint - Michel , Carcassonne , Roquetaillade castle and Pierrefonds . Viollet - le - Duc ' s " restorations " frequently combined historical fact with creative modification . For example , under his supervision , Notre Dame was not only cleaned and restored but also " updated " , gaining its distinctive third tower ( a type of flèche ) in addition to other smaller changes . Another of his most famous restorations , the medieval fortified town of Carcassonne , was similarly enhanced , gaining atop each of its many wall towers , a set of pointed roofs that are actually more typical of northern France . At the same time , in the cultural atmosphere of the Second Empire theory necessarily became diluted in practice : Viollet - le - Duc provided a Gothic reliquary for the relic of the Crown of Thorns at Notre - Dame in 1862 , and yet Napoleon III also commissioned designs for a luxuriously appointed railway carriage from Viollet - le - Duc , in 14th - century Gothic style ( Exhibition 1965 ) . Among his restorations were : Restoration of the Château de Pierrefonds , reinterpreted by Viollet - le - Duc for Napoleon III , was interrupted by the departure of the Emperor in 1870 . Influence on historic preservation . Basic intervention theories of historic preservation are framed in the dualism of the retention of the status quo versus a " restoration " that creates something that never actually existed in the past . John Ruskin was a strong proponent of the former sense , while his contemporary , Viollet - le - Duc , advocated for the latter instance . Viollet - le - Duc wrote that restoration is a " means to reestablish [ a building ] to a finished state , which may in fact never have actually existed at any given time . " The type of restoration employed by Viollet - le - Duc , in its English form as Victorian restoration , was decried by John Ruskin as " a destruction out of which no remnants can be gathered : a destruction accompanied with false description of the thing destroyed . " This argument is still a current one when restoration is being considered for a building or landscape . In removing layers of history from a building , information and age value are also removed which can never be recreated . However , adding features to a building , as Viollet - le - Duc also did , can be more appealing to modern viewers . Publications . Throughout his career Viollet - le - Duc made notes and drawings , not only for the buildings he was working on , but also on Romanesque , Gothic and Renaissance buildings that were to be soon demolished . His notes were helpful in his published works . His study of medieval and Renaissance periods was not limited to architecture , but extended to furniture , clothing , musical instruments , armament , geology and so forth . All this work was published , first in serial , and then as full - scale books , as : Architectural theory and new building projects . Viollet - le - Duc is considered by many to be the first theorist of modern architecture . Sir John Summerson wrote that " there have been two supremely eminent theorists in the history of European architecture - Leon Battista Alberti and Eugène Viollet - le - Duc . " His architectural theory was largely based on finding the ideal forms for specific materials , and using these forms to create buildings . His writings centered on the idea that materials should be used ' honestly ' . He believed that the outward appearance of a building should reflect the rational construction of the building . In " Entretiens sur l ' architecture " , Viollet - le - Duc praised the Greek temple for its rational representation of its construction . For him , " Greek architecture served as a model for the correspondence of structure and appearance . " There is speculation that this philosophy was heavily influenced by the writings of John Ruskin , who championed honesty of materials as one of the seven main emphases of architecture . In several unbuilt projects for new buildings , Viollet - le - Duc applied the lessons he had derived from Gothic architecture , applying its rational structural systems to modern building materials such as cast iron . He also examined organic structures , such as leaves and animal skeletons , for inspiration . He was especially interested in the wings of bats , an influence represented by his Assembly Hall project . Viollet - le - Duc ' s drawings of iron trusswork were innovative for the time . Many of his designs emphasizing iron would later influence the Art Nouveau style , most noticeably in the work of Hector Guimard . His writings inspired some American architects , including Frank Furness , John Wellborn Root , Louis Sullivan , and Frank Lloyd Wright . Military career and influence . Viollet - le - Duc had a second career in the military , primarily in the defence of Paris during the Franco - Prussian War ( 1870 - 1 ) . He was so influenced by the conflict that during his later years he described the idealized defense of France by the analogy of the military history of Le Roche - Pont , an imaginary castle , in his work " Histoire d ' une Forteresse " ( " Annals of a Fortress " , twice translated into English ) . Accessible and well researched , it is partly fictional . " Annals of a Fortress " strongly influenced French military defensive thinking . Viollet - le - Duc ' s critique of the effect of artillery ( applying his practical knowledge from the 1870 – 1871 war ) is so complete that it accurately describes the principles applied to the defence of France until World War II . The physical results of his theories are present in the fortification of Verdun prior to World War I and the Maginot Line prior to World War II . His theories are also represented by the French military theory of " Deliberate Advance " , such that artillery and a strong system of fortresses in the rear of an army are essential . Legacy . Some of his restorations , such as that of the Château de Pierrefonds , have become very controversial because they were not intended so much to recreate a historical situation accurately as to create a " perfect building " of medieval style : " to restore an edifice " , he observed in the " Dictionnaire raisonné " , " is not to maintain it , repair or rebuild it , but to re - establish it in a complete state that may never have existed at a particular moment " . The idea and the very word " restoration " applied to architecture Viollet - le - Duc considered part of a modern innovation . Modern conservation practice considers Viollet - le - Duc ' s restorations too free , too personal , too interpretive , but some of the monuments he restored might have been lost otherwise . The English architect Benjamin Bucknall ( 1833 – 95 ) was a devotee of Viollet - le - Duc and during 1874 - 81 translated several of his publications into English to popularise his principles in Great Britain . An exhibition , " Eugène Viollet - le - Duc 1814 – 1879 " was presented in Paris , 1965 , and a larger , centennial exhibition , 1980 . Later life . In 1874 Viollet - le - Duc resigned as diocesan architect of Paris , and was succeeded by his contemporary , Paul Abadie . In his old age , Viollet - le - Duc relocated to Lausanne , Switzerland , where he constructed a villa ( since destroyed ) . He died there in 1879 .