Considered one of the finest photographers of the twentieth century, Sander's bold style of portrait photography, as well as his typological approach, has had an enormous influence on modern photography. During his apprenticeship in several German studios and his time in his own studio in Austria, he developed his individual style. Then in 1910 Sander moved to Cologne and produced his first large group of photographs, which he later included in his concept "People of the 20th Century". This was created in the mid-1920s and compiled up until the 1950s. He photographed groups of people in his native Germany, classifying them according to their occupations and positions in society.