A monarch is a ruler who holds power for life, usually inheriting the position from a parent or other family member. Kings, queens, emperors, and empresses are all monarchs. Unlike presidents or prime ministers who are elected and serve for a set number of years, monarchs typically rule until they die or choose to step down.

Throughout history, monarchs have held varying amounts of power. Some ruled with absolute authority, making every important decision for their kingdom. Others, like the current King of Denmark or King of Spain, serve mostly ceremonial roles while elected officials actually run the government. Britain's royal family exemplifies this: Queen Elizabeth II reigned for 70 years, and when she died in 2022, her son automatically became King Charles III, but neither held the kind of power British monarchs wielded centuries ago.

A government ruled by a monarch is called a monarchy. Some monarchies still exist today, including Japan, Thailand, and Morocco, though most modern democracies have replaced hereditary rule with elected leaders. When a monarch is crowned, the ceremony is called a coronation.