A monarchy is a form of government where power is passed down through generations within a royal family. The youngest monarch was Mary, Queen of Scots who inherited the throne at just 6 days old, while the longest-reigning current monarch is King Bhumibol Adulyadej of Thailand who took the throne in 1946. A theocracy is a form of government where power is believed to be held by a god or gods and political leadership is governed by religious officials.