"When you're painting out of your consciousness, figures are bound to emerge," Jackson Pollock said in an interview in 1956. An article in "Life Magazine" just a few years earlier had made the US painter famous overnight, originally for paintings like the "Stenographic Figure," above, completed in 1942, at a time when the artist was interested in Native American and Inuit motifs.

In the mid-1940s, Pollock developed a unique technique that made his paintings instantly recognizable. In so-called "drip paintings," paint is dripped or poured on the canvas - no brush needed. "Mural on Indian Red Ground," above, is one of Pollock's most famous paintings - and worth about $250 million.

Latvia-born Mark Rothko wasn't keen on being linked to the representatives of Abstract Expressionism, says art historian Volker Adolphs. "His large-scale fields of color are mainly a reflection of spirituality." In 1970, the artist committed suicide in his studio, presumably because he suffered from depression.

Like Rothko, Barnett Newman is known for his large monochromatic canvasses. Occasionally, he added what he called a "zip" to divide color blocs, as above in the painting "Who's Afraid of Red, Yellow and Blue IV." Along with Rothko, Robert Motherwell and William Baziotes, the son of Russian Jewish immigrants founded the Subjects of the Artist School in New York.

The pseudonym Arshile (Persian: little bear) Gorky (Russian: bitter) gave Vosdanig Manoug Adoian a new identity in 1924. In the early days of Abstract Expressionism, the self-taught painter used relatively small canvasses. He is regarded as a pioneer for the works of his close friend Willem de Kooning, as well as Jackson Pollock.

Willem de Kooning's journey from the Netherlands to the US was adventurous. A stowaway on a freight ship, he entered the country illegally in 1926. Many years later, President Ronald Reagan honored the artist for his life's work. De Kooning and Jackson Pollock were friends, then competitors - but they always inspired each other. De Kooning, for instance, adopted Pollock's large-scale formats.

Cy Twombly's work shows how widely the approaches to Abstract Expressionism vary. Delicate lines, almost like calligraphy, are his trademark. The artist, who died in 2011, lived for many years in Greece and Italy. The 400-square-meter ceiling painting in the Salle des Bronzes at the Louvre Museum in Paris was designed by Twombly - without loops or lines.

In 1948, Robert Motherwell started painting his "Elegy to the Spanish Republic" series - a motif he pursued for the rest of his life. He called his paintings "lamentos" (Spanish for elegies, funeral songs) after the Spanish Civil War (1936-1939). Ovals and squares populate his paintings: Motherwell saw them as a symbol for the testicles of a bull killed in a bullfight.