Complex sentence: There is much debate over why there was such a long interregnum, some authorities believe that it was to allow Boniface to complete his work in Constantinople but the more widely held belief is that there were problems with the election.
Split into simpler sentences: There is much debate over why there was such a long interregnum. Some authorities believe that it was to allow Boniface to complete his work in Constantinople but the more widely held belief is that there were problems with the election.