Complex sentence: Between 1839 and 1843, a new church was built nearby to serve the local community, partly because of the cost of repairing the old church; much of the old church was thereafter demolished, leaving only part of the western end and the central arcade.
Split into simpler sentences: Between 1839 and 1843, a new church was built nearby to serve the local community, partly because of the cost of repairing the old church. Much of the old church was subsequently demolished, leaving only part of the western end and the central arcade.