When Count de Mornay traveled to Morocco in 1832 to establish a treaty supportive of the recent French annexation of Algeria, he took along the Romantic painter Eugène Delacroix. Delacroix not only reveled in the orientalism of the place; he also took it as a new and living model for his works on classical antiquity: "The Greeks and Romans are here at my door, in the Arabs who wrap themselves in a white blanket and look like Cato or Brutus..." He sketched and painted watercolours continuously, writing at the time "I am like a man in a dream, seeing things he fears will vanish from him." He returned to his sketches and memories of North Africa for the rest of his career, with 80 oil paintings like The Fanatics of Tangier and Women of Algiers becoming legendary and influential on artists such as Van Gogh, Gauguin, and Picasso. They were particularly struck by the quality of the light: to Cézanne, "All this luminous colour... seems... that it enters the eye like a glass of wine running into your gullet and it makes you drunk straight away".
Tangier subsequently became an obligatory stop for artists seeking to experience the colours and light he spoke of for themselves—with varying results. Matisse made several sojourns in Tangier, always staying at the Grand Hotel Villa de France. "I have found landscapes in Morocco," he claimed, "exactly as they are described in Delacroix's paintings." His students in turn had their own; the Californian artist Richard Diebenkorn was directly influenced by the haunting colours and rhythmic patterns of Matisse's Morocco paintings.
The multicultural placement of Muslim, Christian and Jewish communities and the foreign immigrants attracted writer George Orwell, writer and composer Paul Bowles, playwright Tennessee Williams, the beat writers William S. Burroughs, Allen Ginsberg and Jack Kerouac, the painter Brion Gysin and the music group the Rolling Stones, who all lived in or visited Tangier during different periods of the 20th century.
In the 1940s and until 1956 when the city was an International Zone, the city served as a playground for eccentric millionaires, a meeting place for secret agents and all kinds of crooks and a mecca for speculators and gamblers, an Eldorado for the fun-loving "Haute Volée". During the Second World War the Office of Strategic Services operated out of Tangier for various operations in North Africa.
Around the same time, a circle of writers emerged which was to have a profound and lasting literary influence. This included Paul Bowles, who lived and wrote for over half a century in the city, Tennessee Williams and Jean Genet as well as Mohamed Choukri (one of North Africa's most controversial and widely read authors), Abdeslam Boulaich, Larbi Layachi, Mohammed Mrabet and Ahmed Yacoubi. Among the best known works from this period is Choukri's For Bread Alone. Originally written in Classical Arabic, the English edition was the result of close collaboration with Bowles (who worked with Choukri to provide the translation and supplied the introduction). Tennessee Williams described it as "a true document of human desperation, shattering in its impact." Independently, William S. Burroughs lived in Tangier for four years and wrote Naked Lunch, whose locale of Interzone is an allusion to the city.
After several years of gradual disentanglement from Spanish and French colonial control, Morocco reintegrated the city of Tangier at the signing of the Tangier Protocol on 29 October 1956. Tangier remains a very popular tourist destination for cruise ships and day visitors from Spain and Gibraltar.