Complex sentence: Four months later, he won the King of the Ring tournament, and not long after he began pursuing the WWF Championship, which he won in October; this capped off a rookie year which is considered by many to be the greatest in professional wrestling history.
Split into simpler sentences: Four months later, he won the King of the Ring tournament and not long after he began pursuing the WWF Championship, which he won in October. This capped off a rookie year which is considered by many to be the greatest in professional wrestling history.