Complex sentence: Joan's son was next in line to succeed King Edward III. Edward III died on 21 June 1377, and Richard became king as Richard II; he was crowned the following month, at the age of 10.
Split into simpler sentences: Joan's son was next in line to succeed King Edward III. Edward III died on 21 June 1377, and Richard became king. He was crowned Richard II the following month, at the age of 10.