Complex sentence: Its holder was not the emperor's biological father, and although its exact functions remain obscure, it is generally hypothesized that it was meant to denote a regent acting as a custodian and tutor over a young emperor.
Split into simpler sentences: Its holder was not the emperor's biological father, and its exact functions remain obscure. It is generally hypothesized that it was meant to denote a regent acting as a custodian and tutor over a young emperor.