Walter Crane's 1886 "Imperial Federation" map dramatically illustrated the extent of the British Empire, which at its height controlled approximately 25% of the world's land surface and governed over 400 million people. Territories under British rule were colored in red or pink (giving rise to the phrase "the sun never sets on the British Empire"). The map served both as a geographic document and a piece of imperial propaganda, promoting the idea of closer federation between Britain and its colonies.