Complex sentence: His mother was the daughter of the Rev. Benjamin Cobley, rector of Dodbrook, Devon, whose son, General Sir Thomas Cobley, signalized himself in the Russian service at the siege of Ismail.
Split into simpler sentences: His mother was the daughter of the Rev. Benjamin Cobley, rector of Dodbrook, Devon. Her brother, General Sir Thomas Cobley, was renowned for his part in the siege of Ismail.