Complex sentence: The Mount Barker Summit was first discovered by Captain Collet Barker in 1830, but he was killed by Aborigines in 1831, so Captain Charles Sturt named Mount Barker after him when he founded it in 1834.
Split into simpler sentences: The Mount Barker Summit was first discovered by Captain Collet Barker in 1830. He was killed by Aborigines in 1831, so Captain Charles Sturt named Mount Barker after him when he founded it in 1834.