Simplify the following text for a Grade 6 native English-speaking person.
Original: It served as capital of the French colony of Saint-Christophe , which consisted of the northern and southern extremities of the island of St. Kitts ( the center was yielded to Britain ) .
Simplified: It served as capital of the French colony of Saint-Christophe , which was the northern and southern extremities of the island of St. Kitts ( the middle was held by Britain ) .