1308, King Albrecht I was murdered by his nephew John Parricida in the neighboring community of Windisch. In memory of this event his wife, Elisabeth of Gorizia-Tyrol, founded Königsfelden Abbey (Cloister of King's Field), a Franciscan monastery and Clarisse convent, in 1310–11 at the site – approximately 200 meters from Brugg. Albrecht's oldest daughter, Agnes of Hungary, the widow of the Hungarian King Andrew III, moved to Königsfelden in 1317 and led it to commercial success, but did not join a religious order. In 1348 she received the sovereign rights to Brugg as well as the neighboring districts of Bözberg (including Lauffohr) and the Eigenamt (including Altenburg) from her brother Duke Albrecht II. These rights lapsed after her death in 1364. Although the town was under Habsburg control, there were still the beginnings of an independent polity. In the 1350s Brugg agreed to association, or Burgrecht, treaties with Baden and Mellingen (1351) and with the Cloister of Wittichen in the upper Kinzig Valley (1353). The departments of Bözburg and Eigenamt, upon their reversion of Habsburg control in 1364, also fell under the military leadership of the town. During this time the Austrians regularly assembled their armed forces in Brugg, as Duke Leopold III did in 1386 prior to the Battle of Sempach. Conquest and Conflict Frederick IV fell into disregard at the Council of Constance in 1415, after he assisted the flight of the opposition Pope John XXIII. In response, Holy Roman Emperor Sigismund requested the Swiss to take control of Aargau. Bern did not hesitate and dispatched troops at once. The residents of Brugg did not resist the invaders and allowed them to enter the town unopposed. In return Bern left the town alone. The town and the Eigenamt, in turn, found themselves in the northeasternmost section of Bern's subject territories, known as Bernese Aargau. At the same time, the Habsburgs relinquished control of Schenkenberg, originally in the district of Bözberg, to creditors they had pledged the territory to following their loss in the Battle of Sempach. This left Brugg in a predicament as its periphery and forest on the Bruggerburg along the northern bank of the Aare remained outside of the jurisdiction of Bern. Brugg was therefore required to consult regularly with the rulers of Schenkenberg concerning its northern territory. King Frederick III of the House of Habsburg joined with Zürich in 1443 in the Old Zürich War