At that time, the Cape Colony belonged to the Batavian Republic, a French vassal. Because the sea route around the Cape was important to the British, they decided to seize the colony in order to prevent it—and the sea route—from also coming under French control. A British fleet was despatched to the Cape in July 1805, to forestall French troopships which Napoleon had sent to reinforce the Cape garrison. After a British victory, peace was made under the Treaty Tree in Woodstock. It established British rule in South Africa, which was to have many ramifications for the region during the nineteenth and twentieth centuries.