Mainz, Trier and [[Cologne]] (in [[North Rhine-Westphalia]]) were the seats of the three spiritual [[prince-electors]] from the 13th century until 1801 ([[Treaty of Lunéville]]). | Mainz, Trier and [[Cologne]] (in [[North Rhine-Westphalia]]) were the seats of the three spiritual [[prince-electors]] from the 13th century until 1801 ([[Treaty of Lunéville]]). |