Complex sentence: The original foundation, created around 1135, may have been by William FitzJohn de Harptree who was involved in the construction of Richmont Castle in East Harptree which would have overlooked West Harptree.
Split into simpler sentences: The original foundation, created around 1135, may have been by William FitzJohn de Harptree. He was involved in the construction of Richmont Castle in East Harptree, which would have overlooked West Harptree.