In 1278 the
Co-Principality of Andorra was established by a treaty called the
Pareage. It was ruled by
the French head of State, and the Spanish Bishop of Urgell. In 1993 the
system of government was modified to provide for a parliamentary
democracy with the former rulers as titular heads of State.
In 1978 the French postal service issued the stamp
picturing the Preamble to the Treaty of 1278 to mark the 700th
anniversary of the Co-Principality.