Rosenborg Castle in Copenhagen is among the 10 best princely treasures of Europe. It has been preserved in its natural surroundings and about 95% of the more than 1000 objects have survived. The first volume tells the history of the collection and ends with an art historical summary of its contents. This account builds partly upon hitherto unknown evidence, for example travel diaries from foreign archives. The finds offer a new picture of royal political propaganda and of the making of Danish national identity. The last two volumes contain a catalogue raisonne. Each object is listed with an extract of the proper inventories, an illustrated description with reference to parallels abroad, and a bibliography.