Aschaffenburg town and collegiate church as part of the Mainz dominion

Aschaffenburg came to the Electorate of Mainz at the end of the 10th century after the death of Duke Otto I of Swabia and Bavaria (954-982, duke of Swabia from 973, duke of Bavaria from 976) and his sister Mathilde (949-1011). This event is of crucial importance for the history of the town. Only indirect evidence of the transfer is provided by a memorial endowment made by Archbishop Willigis of Mainz (975-1011, archbishop from 975) for himself and Duke Otto and his sister, which is recorded in the oldest Aschaffenburg Gospel. According to this, Otto gave the place (istum locum) to the altar of St. Martin (ad altare sancti Martini confessoris), i.e. to the archdiocese of Mainz. No original document regarding this transfer has survived, so no precise statements can be made about the exact factual circumstances and or the timing. However, it remains questionable whether the collegiate church was already included here. It can be assumed though that it came into the possession of the archbishop of Mainz, if not at the same time as the town, then at the end of the 10th or at the beginning of the 11th century at the latest. The collegiate church’s property, which also included large parts of the Spessart, formed the territorial foundation of Mainz’ position of power on the Lower Main, which was continuously expanded over the centuries. This territory, in which the bishops of Mainz exercised secular rights of rule, was the Mainzer Oberstift with Aschaffenburg as its centre. It comprised the Mainz property on the Lower Main, in Spessart and Odenwald as well as on the Tauber.