Lucerne grew in power, they became interested in the southern portion of what would become the Freie Ämter. In 1394 they acquired the Amt of Merenschwand which gave Lucerne an exclave west of the river Reuss. In the Battle of Sempach, the Habsburg villages of Aristau and Meienberg were destroyed. Following the defeat of 1386, and despite the 1394 peace between the Habsburgs and the Confederation, the Habsburg city of Bremgarten entered into an alliance with Bern in 1407. Conquest of the Aargau On 16 November 1414, Emperor Sigismund called the Council of Constance to settle the Western Schism between the three popes (Benedict XIII, Gregory XII, and John XXIII), all of whom claimed legitimacy. Frederick IV of Habsburg sided with John XXIII. When John XXIII was declared an antipope, he fled the city with Frederick's help. The emperor then declared the Habsburg lands forfeited and ordered the neighboring countries to conquer those lands for the emperor. The city-state of Bern had already pledged their support of the emperor against the Habsburgs in 1414, and so they were ready to invade. The rest of the Confederation quickly followed. The territory was quickly conquered in 1415 by the Confederation. Under Habsburg rule Aargau was divided into multiple sections (), which were maintained under the Confederation. Bern, Lucerne and Zurich were each given a portion of the conquered region to administer. The rest of the Freie Ämter were collectively administered as subject territories by the rest of the Confederation – effectively a condominium. Muri Amt was assigned to Zurich, Lucerne, Schwyz, Unterwalden, Zug and Glarus, while the Ämter of Meienberg, Richensee and Villmergen were first given to Lucerne alone. The final boundary was set in 1425 by an arbitration tribunal and Lucerne had to give the three Ämter to be collectively ruled. The four Ämter were then consolidated under a single Confederation bailiff into what was known in the 15th century as the Waggental Bailiwick (). In the 16th century, it came to be known as the Vogtei der Freien Ämter. While the Freien Ämter often had independent lower courts, they were forced to accept the Confederation's sovereignty. Finally, in 1532 the canton of Uri became part of the collective administration of the Freien Ämter. From the Reformation to the creation of Aargau At the time of Reformation the majority of the Ämter converted to the new faith. In 1529 a wave