Complex sentence: Members of the Parliament of Ireland were only elected by Protestants, as the Roman Catholic property owners had been disenfranchised in 1728, and the majority Catholics had, over the previous century, been progressively stripped of other rights as well.
Split into simpler sentences: Members of the Parliament of Ireland were only elected by Protestants, as the Roman Catholic property owners had been disenfranchised in 1728. The majority Catholics had, over the previous century, been progressively stripped of other rights as well.