Complex sentence: After going through four different flagship burgers in twenty years, Harvey's introduced the Great Canadian as its flagship burger in 2010; it was discontinued in 2013; it was replaced by the Angus burger, which has served as the chain's flagship burger since then.
Split into simpler sentences: After going through four different flagship burgers in twenty years, Harvey's introduced the Great Canadian as its flagship burger in 2010. It was discontinued in 2013 and replaced by the Angus burger, which has served as the chain's flagship burger since then.