Kings and queens of the United Kingdom. In the past, kings and queens had great power in the United Kingdom. Today, the duties of the British monarch (king or queen) are mainly ceremonial. However, he or she serves as a symbol of unity for the British people and is generally regarded with a high level of respect.

The role of the monarch in British politics is part of the unwritten British constitution. As a constitutional monarch, the king or queen serves as head of state. He or she reigns (holds office) with the aid and agreement of an elected Parliament. For the most part, Parliament controls the government.

Before the 1600's, monarchs led the nobility and managed state affairs through ministers they appointed. They also formed government policy. Parliament served as a sort of advisory council rather than as a governing body. In the 1640's, Parliament and its supporters defeated the reigning king, Charles I, in a civil war. Charles was executed in 1649, and the Commonwealth of England replaced the monarchy. Under the new government, a committee of Parliament ruled England. In 1660, the monarchy was restored. After that date, however, Parliament gradually took control of the government and the monarchy's power declined.

Kings and queens reigned in what is now the United Kingdom long before the emergence of England, Ireland, Scotland, and Wales as separate political divisions. When the Romans first arrived in Britain in 55 B.C., powerful chiefs ruled tribes of native Britons. Between the late A.D. 300