Complex sentence: Somerled was wounded in the leg by a javelin and then killed by the sword of his opponents as well as his eldest son Gillecallum, from his first marriage, who died by his side.
Split into simpler sentences: Somerled was wounded in the leg by a javelin and then killed by the sword of his opponents. Somerled's eldest son Gillecallum, from his first marriage, died by his side.