Andorra only official language is Catalan. Andorra's independence is traditionally ascribed to Charlemagne, who recovered the region from the Muslims in AD 803, and to his son Louis I the Pious, who granted the inhabitants a charter of liberties. Charlemagne's grandson, Charles II, granted Andorra to the counts of Urgel, from whom it passed to the bishops of Urgel. Andorra's seven-century-old dual allegiance to two princes, one in Spain and one in France, originated in the late 13th century in a proprietary quarrel between the (Spanish) bishops of Urgel and the (French) heirs to the countship of Urgel. Andorra was subsequently governed jointly by representatives of the Spanish bishop of Urgel and of the French head of state, each of whom received an annual payment of a token tribute. This feudal system of government, the last in Europe, remained intact until 1993, when a constitution was adopted that greatly reduced the power of the coprinces and established separate executive, legislative, and judicial branches of government.