The architect Antonio Croci was born in Mendrisio on April 7th 1823. In 1837, he applies to the Brera Academy of Fine Arts in Milan where he studied ornament, architecture, aesthetics and perspective. Documents kept in the historical archive in Mendrisio witness of the presence of Croci, on October 24th 1847, in Constantinople, from where he returns home in 1858. It is still not clear wether he spent the entire time in Turkey, as suggested by a genealogy record of the Croci family preserved at the Cantonal archive in Bellinzona where one can read the mention "resident in Izmir" next to Antonio's name. Two records in the Croci Fund representing the survey of the campanile of Saint Spiridon and the section of the projected elevation were first thought to be dated to the time Croci was in Turkey or at least in the Orient. Through this research, it has been possible to establish that the campanile is located in Iasi in Rumania and that the project could be prior to 1858, therefore before his return from Turkey. According to the biography by Ambrogio Croci, Antonio's great-grandson, published in the "Corriere del Ticino" in 1937, the architect had lived in Russia and Izmir where he built a mosque and a synagogue while building two hotels in Ticino: the "Mendrisio" in the city of the same name and the "Bellavista" on Monte Generoso; this biography also claims he designed a moorish-style villa in Cernobbio, on Lake Como. This study has revealed the attribution of all these works to be unsubstantiated. The presence of Antonio Croci in Nice is attested from 1869 onwards through his collaboration on the construction of the castle of Valrose, built for Paul von der Wies, baron of Saint Petersburg, who was simultaneously having the castle of Trevano built near Lugano by a team of architects. Despite the project being often attributed to Croci, his contribution was only marginal. Between 1861 and 1865, Antonio Croci submitted a neo-gothic project for the 16th century parochial church of San Giorgio to Ernen in Wallis; the monument underwent restoration in 1965 that returned it to its original condition, before the 19th century alterations. Croci will return to Wallis in 1874 with a project for the church of Sant'Anna in Lax, the construction of which will only partially resemble the architect's initial design. Antonio Croci returns regularly to Ticino where in 1861 he takes part in the competition for the parochial church in Mendrisio. After mixed fortunes listed here in detail for the first time, it will finally be commissioned to Luigi Fontana. It is generally assumed that Croci, who had returned to Mendrisio in 1863, was responsible for the design of the Franchini chapel: proof has been found confirming this assertion. At the beginning of the 1870s', Antonio Croci leaves for Argentina where he frequents the circle of Ticino emigrants, making the acquaintance of the Bernasconi family. They intend to return to their homeland and therefore commission a summerhouse in Mendrisio, currently named Villa Argentina. During the same decade, he is given the opportunity to collaborate with the sculptor Vincenzo Vela on the mausoleum for the Duke of Brunswick in Geneva. His main works were built in his hometown and include his private house, the Carlasch, his masterpiece, summa of poetics, compositional mastery and constructive talent. Antonio Croci died in Mendrisio on December 2nd 1884 without direct descendants. The house he lived in until his death and the documents it contained went to his brother Giuseppe. The archive was then divided, mostly dispersed and only recently partially recovered. The different pieces are currently collected in a single fund at the state archive in Bellinzona. The reconstruction of the architect's life and the identification of many drawings related to unknown projects, works and places still bear many uncertainties. The research is divided into five main themes starting with the questions regarding the formative years, followed by the projects in "faraway lands" before examining the works designed in Ticino. The last chapters offer an in-depth view of the polygonal plans and a catalogue of the more than 200 drawings that cover Croci's entire production, compiled in the second volume. This study has required the verification of each biographical notice through enquiries in the archives of the places in which Antonio Croci's presence is accounted for. The thesis demonstrates how many works have been casually attributed to Croci, recalls the history of each project, underlining many of their aspects including an analysis of the compositional and structural systems.