His understanding of the possibilities of painting was evolving rapidly; from studying Hals he learned to portray the freshness of a visual impression, while the works of Paolo Veronese and Eugène Delacroix taught him that colour can express something by itself. This led to his enthusiasm for Peter Paul Rubens and inspired his sudden departure for Antwerp, Belgium, where the greatest number of Rubens’s works could be seen. The revelation of Rubens’s mode of direct notation and of his ability to express a mood by a combination of colours proved decisive in the development of van Gogh’s style. Simultaneously, van Gogh discovered Japanese prints and Impressionist painting. All these sources influenced him more than the academic principles taught at the Antwerp Academy, where he was enrolled. His refusal to follow the academy’s dictates led to disputes, and after three months he left precipitately in 1886 to join Theo in Paris. There, still concerned with improving his drawing, van Gogh met Henri de Toulouse-Lautrec, Paul Gauguin, and others who were to play historic roles in modern art. They opened his eyes to the latest developments in French painting. At the same time, Theo introduced him to Camille Pissarro, Georges Seurat, and other artists of the Impressionist group.
Between 1885 and his death in 1890, Van Gogh appears to have been building an oeuvre, a collection that reflected his personal vision, and could be commercially successful. He was influenced by Blanc's definition of style, that a true painting required optimal use of colour, perspective and brushstrokes. Van Gogh applied the word "purposeful" to paintings he thought he had mastered, as opposed to those he thought of as studies. He painted many series of studies; most of which were still lifes, many executed as colour experiments or as gifts to friends. The work in Arles contributed considerably to his oeuvre: those he thought the most important from that time were The Sower, Night Cafe, Memory of the Garden in Etten and Starry Night. With their broad brushstrokes, inventive perspectives, colours, contours and designs, these paintings represent the style he sought.
In July 1869 Van Gogh's uncle Cent obtained a position for him at the art dealers Goupil & Cie in The Hague. After completing his training in 1873, he was transferred to Goupil's London branch at Southampton Street, and took lodgings at 87 Hackford Road, Stockwell. This was a happy time for Van Gogh; he was successful at work, and at 20 was earning more than his father. Theo's wife later remarked that this was the best year of Vincent's life. He became infatuated with his landlady's daughter, Eugénie Loyer, but was rejected after confessing his feelings; she was secretly engaged to a former lodger. He grew more isolated, and religiously fervent. His father and uncle arranged a transfer to Paris in 1875, where he became resentful of issues such as the degree to which the firm commodified art, and was dismissed a year later.
Ill from drink and suffering from smoker's cough, in February 1888 Van Gogh sought refuge in Arles. He seems to have moved with thoughts of founding an art colony. The Danish artist Christian Mourier-Petersen became his companion for two months, and at first Arles appeared exotic. In a letter, he described it as a foreign country: "The Zouaves, the brothels, the adorable little Arlésienne going to her First Communion, the priest in his surplice, who looks like a dangerous rhinoceros, the people drinking absinthe, all seem to me creatures from another world."
Van Gogh learned about Fernand Cormon's atelier from Theo. He worked at the studio in April and May 1886, where he frequented the circle of the Australian artist John Peter Russell, who painted his portrait in 1886. Van Gogh also met fellow students Émile Bernard, Louis Anquetin and Henri de Toulouse-Lautrec – who painted a portrait of him in pastel. They met at Julien "Père" Tanguy's paint shop, (which was, at that time, the only place where Paul Cézanne's paintings were displayed). In 1886, two large exhibitions were staged there, showing Pointillism and Neo-impressionism for the first time, and bringing attention to Georges Seurat and Paul Signac. Theo kept a stock of Impressionist paintings in his gallery on boulevard Montmartre, but Van Gogh was slow to acknowledge the new developments in art.
During the last six or seven months of the year 1889, he has also created at least fifteen paintings of olive trees, a subject which he considered as demanding and compelling. Among these works are Olive Trees with the Alpilles in the Background (1889), about which in a letter to his brother Van Gogh wrote, "At last I have a landscape with olives".While in Saint-Rémy, Van Gogh spent time outside the asylum, where he painted trees in the olive groves. In these works natural life is rendered as gnarled and arthritic as if a personification of the natural world, which are, according to Hughes, filled with "a continuous field of energy of which nature is a manifestation".