Mario Tamagno was educated at the Accademia Albertina in Turin, where he taught for five years after graduating in 1895. In 1900, he traveled to Siam (today’s Thailand) to work for the Siamese government. There, he collaborated with another Italian architect, Annibale Rigotti, to create important buildings in Bangkok. In 1907, Rigotti and Tamagno designed the Ananda Samakhom Throne Hall in the Royal Plaza, a spectacular domed structure completed in 1915. Tamagno also built the Suan Kularb Residential Hall and Throne Hall in Dusit Garden, and the Hua Lampong Railway Station in 1910-1912. In 1913 King Rama VI (1910 – 1925) entrusted Tamagno and Rigotti with the reconstruction of the Santa Cruz Church (the Portuguese church was first built in 1770 and rebuilt in 1835). Tamagno also contributed to building the Neilson Hays Library in Surawongse Road. After completion of his first government contract in 1925, he was asked to continue on, and the Siamese government commissioned him to complete the Villa Norasing (today’s House of Government). He designed the Pavilion of Siam for the 1911 Exposition in Turin. He returned to Italy in May 1926.