Complex sentence: It is from this point that Wolverhampton is generally considered a Royal Peculiar or Peculier, although it had claimed and vindicated its status as a royal chapel, independent of the diocesan authorities, for many centuries already.
Split into simpler sentences: It is from this point that Wolverhampton is generally considered a Royal Peculiar or Peculier. In fact, it had claimed and vindicated its status as a royal chapel, independent of the diocesan authorities, for many centuries already.