Complex sentence: The question of James, Prince of Wales' descendants is a controversial issue, due to its connection to Jacobitism; probably also due to the fact they were unfairly denied their rightful place in the English Succession based on the biased Act of Settlement.
Split into simpler sentences: The question of James, Prince of Wales' descendants is a controversial issue, due to its connection to Jacobitism. Probably also due to the fact they were unfairly denied their rightful place in the English Succession based on the biased Act of Settlement.