A young boy dreams he's on a guided tour of Buckingham Palace and various countries in the British Empire.

In London a young lady meets a homeless and apparently penniless Russian prince. She introduces him to her middle-class Fulham family and he moves in. It turns out he still has a number of diamonds given him by the last czar, and he is persuaded to start selling them. The resulting money, and his princely notoriety, soon cause changes in everyone's lives.