Philip was only four years old when his mother died in 1482, resulting in him succeeding her as ruler of the Burgundian possessions under the guardianship of his father. A period of turmoil ensued which witnessed sporadic hostilities between, principally, the large towns of Flanders (especially Ghent and Bruges) and the supporters of Maximilian. During this interregnum, Philip became caught up in events and was even briefly sequestered in Bruges as part of the larger Flemish campaign to support their claims of greater autonomy, which they had wrested from Mary of Burgundy in an agreement known as the Great Privilege of 1477. By the early 1490s, the turmoil of the interregnum gave way to an uneasy stand-off, with neither French support for the cities of the Franc (Flanders), nor Imperial support from Philip's grandfather, Emperor Frederick III proving decisive. Both sides came to terms in the Treaty of Senlis in 1493, when Emperor Frederick died and Philip's father Maximilian became the new emperor. This smoothed over the internal power struggle as the two sides agreed to make the 15-year-old Philip crown prince in the following year.