The settlement of Andorra la Vella has been the principal city of Andorra since 1278 when the French and the Episcopal co-princes agreed to joint suzerainty. Andorra la Vella's old town—the ''Barri Antic''—includes streets and buildings dating from this time. Its most notable building is the ''Casa de la Vall''—constructed in the early sixteenth century—which has been the state's parliamentary house since 1702. Andorra la Vella was, during this period, the capital of a largely isolated and feudal state, which retained its independence due to this principle of co-sovereignty.