Complex sentence: During the Civil War when the estate was estimated to be worth £800 per annum, he married Ann Smyth, daughter of Richard Smyth of Credenhill; their fourth and eldest surviving son, William Dansey was a captain in the King's army.
Split into simpler sentences: During the Civil War when the estate was estimated to be worth £800 per annum. He married Ann Smyth, daughter of Richard Smyth of Credenhill; their fourth and eldest surviving son, William Dansey was a captain in the King's army.