Hoefnagels made many landscape drawings during his travels in Europe. These later served as the models for engravings for Ortelius' "Theatrum orbis terrarum" (1570) and Braun's "Civitates orbis terrarum" (Cologne, 1572–1618). The Civitates orbis terrarum was with its six volumes the most extensive atlas of its time. Hoefnagel worked intermittently on the Civitates his whole life and may have acted as an agent for the project, by commissioning views from other artists. He also completed more than 60 illustrations himself, including various views in Bavaria, Italy and Bohemia. He enlivened the finished engravings with a Mannerist sense of fantasy and wit by using dramatic perspectives and ornamental cartouches. Due to the topographical accuracy he heralded the realist trend in 17th-century Netherlandish landscape art.