Original sentence: Madagascar was formerly annexed by the French in 1896, overseen by the first Resident General Laroche.The situation quickly changed when his former ally, the British, recognized a French Protectorate of Madagascar in September, 1890, in return for eventual control over Zanzibar  and as part of an overall definition of spheres of influence in Africa.They finally reached the city and began the assault in the last week of September, 1895
Edited sentence: Madagascar was formally annexed by the French in 1896, overseen by the first Resident General Laroche.The situation quickly changed when his former ally, the British, recognized a French Protectorate of Madagascar in September 1890, in return for eventual control over Zanzibar  and as part of an overall definition of spheres of influence in Africa.They finally reached the city and began the assault in the last week of September 1895