Complex sentence: When World War I broke out in 1914 he joined the Colombo Town Guard, however he and his brothers were imprisoned without charges during the 1915 riots and faced the prospect of execution since the British Governor Sir Robert Chalmers considered the temperance movement as seditious.
Split into simpler sentences: When World War I broke out in 1914 they joined the Colombo Town Guard. The brothers were imprisoned without charges during the 1915 riots and faced the prospect of execution since the British Governor Sir Robert Chalmers considered the temperance movement as seditious.