Complex sentence: Although the British annexed Upper Burma in 1885, the Kokang transferred local soveriegnty to Great Britain, the Yang family continued to maintain power in a district within the state of Hsenwi North.
Split into simpler sentences: Although the British annexed Upper Burma in 1885, the Kokang transferred local soveriegnty to Great Britain. However, the Yang family still maintained power in a district within the state of Hsenwi North.