Ion Theodorescu-Sion graduated from the School of Fine Arts in Bucharest with George Demetrescu Mirea and Ipolit Strâmbu as teachers. He gained recognition by obtaining a scholarship, granted by the Ministry of War, to study in Paris. He was sent by the General  Headquarters to paint the scenes of war but ended up fighting on the front. Sion studied in the great capitals of Europe. He was a professor at the Academy of Fine Arts in Bucharest and part of the founding committee of the Society of Visual Artists.

Together with other artists, he contributed to the decoration of the Royal Palace in Bucharest by painting the four decorative panels in the Throne Hall. Sion was an artist with a chameleonic style, who has shown throughout his career that he can change his style and motifs countless times, delivering new insightful meanings every time. Flexible in thinking and building his composition in a dynamic style, he managed to perfectly materialise his own ideas on canvas. At this point in his career he already owned a fantastic draughtsmanship so he added colours to his subjects, demonstrating chromatic and technical skills.

The artist had an intense life and towards the end he dedicated his art to still lifes with flowers and fruits, a choice influenced by his health problems. This period begins in the ‘30s, succeeding in giving to posterity true masterpieces inspired by nature. 

Nicolae Tonitza says about the young Sion: “[...] the fresco painting, in which the “specific Romanian” elements abound in a masterful, pyramidal combination. In this medium, Th. Sion is unbeatable” (Nicolae Tonitza, “Writings about art”, second edition, page 130, Ed. Meridiane, Bucharest, 1964).