I’ve been trying to understand just what this “kirchegeschichtliches Epitome” text is that all the articles about Philip of Side mention. The catalogue of fragments referred to it quite a bit.
It seems it’s a text whose existence is inferred (don’t you hate that?). Apparently there are three 14th century manuscripts containing excerpts from church histories of various sorts. If you compare these, there’s enough commonality that they can’t be independent. They must all derive from some earlier epitome of church history. Then there are a couple of pages in Milan, which seem to derive from a copy of that earlier epitome. The conclusion of De Boor, when printing the fragments of Philip of Side, was that this epitome was the source for all the fragments now extant.
The epitome consists of snippets from Eusebius’ Church History, plus additions from sources unspecified; then material from the Historia Tripartita (i.e. Socrates, Sozomen, Theodoret), plus some stuff from the now lost history of Gelasius of Caesarea. It ran from the time of Christ up to the reign of the emperor Phocas (610), so was presumably written at that time. The Christian History of Philip of Side must have been one of the minor sources.