Complex sentence: There were three other Steadings which were disestablished and incorporated into the Protector's personal domain; their Steadholders were the leaders of the Faithful (forefathers of the Masadans) during the Grayson Civil War.
Split into simpler sentences: There were three other Steadings which were disestablished and incorporated into the Protector's personal domain. Their Steadholders were the leaders of the Faithful (forefathers of the Masadans) during the Grayson Civil War.