Complex sentence: He married secondly Elizabeth Gill (née Fellgate) and had two sons, one of whom, William Aston junior, killed a Mr Keating in a street brawl in Dublin in 1686 and was hanged for his murder.
Split into simpler sentences: He married secondly Elizabeth Gill (née Fellgate) and had two sons. One of Aston's sons by Elizabrth, William Aston junior, killed a Mr Keating in a street brawl in Dublin in 1686 and was hanged for his murder.