Complex sentence: His son was Benjamin Hall, 1st Baron Llanover, a civil engineer and politician who as Commissioner of Works was notable for the construction of the Clock Tower of the Palace of Westminster, of which the famous bell is accordingly known as'Big Ben'.
Split into simpler sentences: His son was Benjamin Hall, 1st Baron Llanover, a civil engineer and politician who as Commissioner of Works was notable for the construction of the Clock Tower of the Palace of Westminster. Some hold that the famous bell is accordingly known as'Big Ben'.