During Denmark's Golden Age, literature centred on Romantic thinking. It was introduced in 1802 by the philosopher Henrik Steffens who gave a successful series of lectures at Elers Kollegium. He presented the main themes of German romanticism, emphasising the relationship between nature, history and mankind. The movement was maintained by the romanticists, especially Adam Oehlenschläger (1779–1850). Remembered today for his "Digte" (1803) and "Poetiske Skrifter" (1805), Oehlenschläger quickly became the leading poet in Denmark. Bernhard Severin Ingemann (1789–1862) also published a collection of romantic poems before producing first a number of plays, then a successful series of novels and finally a number of fine religious poems which, after being set to music, became an important addition to the hymns sung in Danish churches.