Complex sentence: When the British East India Company took control of Assam in 1826, Britain steadily expanded its domain over all of the Naga Hills except the Tuensang area in the northeast by 1892.
Split into simpler sentences: When the British East India Company took control of Assam in 1826, Britain steadily expanded its domain over modern Naga Hills. The British governed all of the Naga Hills except the Tuensang area in the northeast by 1892.