Complex sentence: George was an upholsterer and a leading light in Royston Tradesmens' Benefit Society which spent its profits in building houses and erected enough to make two streets, one of which they named Morton Street.
Split into simpler sentences: George was an upholsterer and a leading light in Royston Tradesmens' Benefit Society which spent its profits in building houses. They made two streets, one of which they named Morton Street.