Complex sentence: Having stood for about 1,150 years, that church was demolished in 1809 at the instigation of the then vicar, Christopher Naylor, partly because it had been at imminent risk of being washed away by the sea through coastal erosion.
Split into simpler sentences: Having stood for about 1,150 years, that church was demolished in 1809 at the instigation of the then vicar, Christopher Naylor. The old church had been at imminent risk of being washed away by the sea through coastal erosion.