Théophile de Bock initially worked for the Railways, where he could not keep his hands off his drawing tools and paintbrush during work. So his career came to an abrupt end. De Bock came under the care of the man of letters Johan Kneppelhout, who saw De Bock's talent. But de Bock was not charmed by his patron's meddling and decided to follow his own path. He was apprenticed to J.W. van Borselen in The Hague and later with the famous J.H. Weissenbruch. But it was mainly Jacob Maris who would influence him. From the moment Maris returned from Barbizon in 1872, where he had practiced painting from nature in the open air in the woods of Fontainebleau, De Bock could regularly be found in his studio. This is where his preference for painting forest and dune views arose. De Bock was a great admirer of the painters of the French Barbizon School, especially Camille Corot, and spent the period 1878-1880 in Barbizon. The influence of this can be found in many of his paintings and he found his inspiration in the nature of the Veluwezoom around Oosterbeek and Renkum in the Netherlands.
De Bock was a quick learner and hard worker. When he was 21 years old, his first painting was on display at the Living Masters exhibition in The Hague. From 1877 to 1881, de Bock rented a studio in The Hague, together with fellow artists Tony Offermans and Jozef Neuhuys. In France, De Bock met Vincent van Gogh during one of the study trips. The contact between them was further strengthened in the years 1881-1883 when Van Gogh stayed in The Hague. From time to time Van Gogh reported to his brother Theo about De Bock's 'painter's temperament', who 'has not yet said his last word'. Only in the painting of figures did Van Gogh think that De Bock fell short.
De Bock was a popular guest in The Hague club life and a good organizer. When Pulchri Studio refused to exhibit the work of progressive artists, including Van Gogh, he took the initiative to set up the Haagse Kunstkring. He was a member of Arti et Amicitiae in Amsterdam and the Hollandsche Teekenmaatschappij. He was also doing well financially. His paintings, the paint often still 'wet', sold well, also in England, the United States and Canada. In addition, Hendrik Willem Mesdag asked him to paint the sky and the dunes on Panorama Mesdag.
After a stay in Diepenveen, with trips to the Zuiderzee and Zwartsluis, his 'shipwright yard period' as he himself called it, De Bock was at the end of the 1980s regularly working in the Oranjerie of Castle Doorwerth, his 'summer residence' . In 1895 the whole family moved to nearby Renkum. There he became honorary chairman of the artists' association Pictura Veluvensis. De Bock's importance to Gelderland lies in the imagination of the Veluwe landscape. While the Veluwezoom was already popular with painters in the middle of the 19th century with J. W. Bilders as the central figure, in the last quarter of this century this area with places such as Oosterbeek, Renkum and Wolfheze again had great appeal. Now an artists' colony formed here around the Bock.
In 1902 De Bock moved to Haarlem. 'Gelderland eventually had something heavy.' Here he died in 1904 at the age of 53.