Complex sentence: On the point in the late 1860s Lavernock Fort gun battery was built by the Royal Commission and completed in 1870, with three 7 muzzle loading cannons to protect the channel approaches to Cardiff and Bristol shipyards.
Split into simpler sentences: On the point in the late 1860s Lavernock Fort gun battery was built by the Royal Commission. It was completed in 1870, with three 7 muzzle loading cannons to protect the channel approaches to Cardiff and Bristol shipyards.