no rocks, waterfalls, high mountains or romantic valleys. Proud, sublime nature is not to be found in our land’. With that in mind, in the summer of 1834 he moved to the old Ducal capital of Cleves, Germany, where he found his ideal subject matter in the region of the Ahr, Ruhr and Rhine. Soon large oak trees, winding paths and panoramic views filled his paintings with an artful blend of minute detail and atmospheric mood. In Cleves, where he would spend the rest of his life, Koekkoek painted his most important landscapes, ranging from extensive river valleys to idyllic forest views dominated by one or more oaks. He often dramatized his trees as a means to emphasize man's paltriness in comparison to nature. By 1841, Koekkoek had earned such regard from his fellow artists that he decided to publish a book of lessons for students, Herinneringen en Mededeelingen van eenen Landschapsschilder ("Recollections and Communications of a Landscape Painter"), in which he aired the view that an artist must, above all, stay true to nature through meticulous observation and rigorous draughtsmanship. This seminal work took the form of a leisurely journey along the Rhine, pointing out to the reader various qualities of nature and landscape. The same year, by popular demand from young artists eager to receive his tuition, Koekkoek founded his own drawing academy (Zeichen Collegium), and in his footsteps, many artists travelled to the former ducal residence seeking instruction from the great master at the academy, among them Frederik Marinus Kruseman, Lodewijk Johannes Kleijn, and Johann Bernard Klombeck. Closely adhering to their master's principles expressed in his writings and in his paintings, these artists collectively gave rise to the school of landscape painting referred to as 'Cleves Romanticism', blending realism with a pervading idealized atmosphere. He advised his students to study nature closely, to observe the qualities of light at dawn and at sunset and the development of storms. He also guided his students in the examination of Dutch seventeenth century masters. The 1840s-50s saw Koekkoek at the very height of his genius. In November 1859 Koekkoek suffered from a major stroke which effectively ended his career as a painter. He died April 5, 1862, in his beloved town of Cleves. Work Koekkoek's own paintings reveal a careful study and synthesis of Dutch seventeenth-century painters. His art is firmly rooted in the great Dutch romantic tradition established by