フォントノワの戦いの契機はなんですか？
Saxe went on the offensive in April 1745 with a large French army, looking to build on the previous year's gains. His initial aim was to take control of the upper Scheldt basin and thereby gain access to the heart of the Austrian Netherlands. To these ends, he first besieged the fortress of Tournai, protecting the siege with his main force about 5 miles (~9 km) southeast of the town. In order to relieve Tournai, the allies first decided to attack Saxe's position – a naturally strong feature, hinged on the village of Fontenoy and further strengthened by defensive works.
to relieve Tournai, the allies first decided to attack Saxe's position