In 1915 Iacovleff returned to St. Petersburg. In the same year, his work was presented at the "World of Art" exhibition. He made sketches of frescoes for the Firsanova mansion in Moscow and the art cabaret "Prival of Comedians" in St. Petersburg.

Iacovleff taught women's architectural courses and organized his own artistic movement (along with Shukhaev, Radlov and Kardovsky): St. Luke's Guild. In 1917 Iacovleff received a scholarship to study in the Far East. In 1917-1919 he traveled to Mongolia, China and Japan. Upon his return from the East, Iacovleff settled in Paris and received French citizenship. In 1924-1925 he took part in Citroen exhibitions devoted to the Sahara Desert and Equatorial Guinea. His African paintings were a great success, and in 1926 the French government awarded him the Legion of Honor. In 1928 Iacovleff organized a large personal exhibition in Moscow. From 1931-1932 he worked as an art advisor on another Citroen expedition, this time to Asia. He traveled to Syria, Iran, Afghanistan, Mongolia and China. Throughout his travels, Iacovleff created many exotic paintings.

From 1934-1937 the artist was head of the art department of the School of the Museum of Fine Arts in Boston, Massachusetts. Iacovleff spent the last months of his life in Paris and on the island of Capri. Iacovleff died in Paris in 1938. His works are collected at the State Russian Museum in St. Petersburg, the State Tretyakov Gallery in Moscow, the Art Gallery of New South Wales in Sydney, Australia, the Harvard University Museum of Art, Massachusetts, the Philadelphia Museum of Art, USA, and many other museums and distinguished collections in Europe and America.