Complex sentence: He allowed extramural burials in its unconsecrated soil, which became popular with Nonconformists--those Protestant Christians who practised their faith outside the Church of England: unlike Anglican parish churchyards, the burial ground was open for interment to anyone who could afford the fees.
Split into simpler sentences: He allowed extramural burials in its unconsecrated soil, which became popular with Nonconformists--those Protestant Christians who practised their faith outside the Church of England. The burial ground was open for interment to anyone who could afford the fees.