Complex sentence: Robert followed his father into the law, becoming King's Serjeant in c.1348, Attorney General for Ireland in 1355 Ball p.83 and Chief Justice of the Irish Common Pleas in 1358; he held the latter office for 20 years.
Split into simpler sentences: Robert followed his father into the law, becoming King's Serjeant in c.1348 and Attorney General for Ireland in 1355 Ball p.83. He became Chief Justice of the Irish Common Pleas in 1358; he held the latter office for 20 years.