Complex sentence: The two currently regularly used British Chapels Royal are located in St. James's Palace in London: the Chapel Royal and the Queen's Chapel; since such establishments are outside the usual diocesan structure, they are classified as royal peculiars.
Split into simpler sentences: The two currently regularly used British Chapels Royal are located in St. James's Palace in London: the Chapel Royal and the Queen's Chapel. Since such establishments are outside the usual diocesan structure, they are classified as royal peculiars.