of these coats of arms are based on an earlier sigil or city seal used to authenticate documents in the Middle Ages. The coat of arms of Berlin depicts a black bear upon a white shield, crowned overall in the fashion of German/Nordic city-states. City seals of Berlin have prominently featured a bear since the 14th century, and bears were used as supporters even earlier. An eagle appeared on the first seal of Berlin in the 1250s, and was soon supported by bears. The eagle and the bear changed their positions and attitudes but remained together in the seals and arms of Berlin until around 1600 when the eagle went on hiatus, returning by 1700 and remaining into the 20th century. Modern arms either represent the history of the state, or their parts, or both. For example, the arms of Baden-Württemberg specify that they represent Baden, Württemberg, Hohenzollern, Palatinate, Franconia and Further Austria. The Red Eagle of Brandenburg is said to have been adopted as early as the 10th century and endures today. A 14th-century seal of Bremen featured a key, symbolizing Saint Peter, and this symbol endures to the present coat of arms of Bremen. The coat of arms of Hamburg, since a city seal dating from 1245, have featured two stars over a white castle upon a red shield. Note that the stars have six points rather than five, in the custom of German/Nordic heraldry. Trier, the oldest city in Germany, is represented by a haloed Saint Peter, the patron saint of the city, holding the key to the city in his right hand and the Bible in his left. Older city seals show Saint Peter holding up his key and surrounded by the city wall, often with the inscription Sancta Treveris ("Sacred Trier"). From the 13th century, the Archbishop of Trier was one of the three ecclesiastical Prince-electors of the Holy Roman Empire. The arms of Weimar, since the 14th century, has depicted a black lion rampant upon a semy of red hearts on a gold shield. Ecclesiastical heraldry There was no structured Church heraldry until the 17th century, when a formalized system for ecclesiastical hats attributed to Pierre Palliot came into use. The full system of emblems around the shield was regulated in the Catholic Church by the letter of Pope Pius X Inter multiplices curas of February 21, 1905. The composition of the shield itself