English to Arabic Art/Literary History history

the text is historical, it is about the Marcus aurelius,empror of Rome till 180, he had wars with the tribes across the Danube, the sentence in which this word is mentioned is sort of ambigious for me, so could you please help explain the meaning: it is as follows:
the sources available for piecing together an account of these wars is similar to that concerning Trajan's wars. The only narrative source that we know of is Dio Cassius, who again is preserved only in excerpts made by Xiphilinus. Accordingly, the vignettes that struck the abridger's interest are often hard to ascribe chronologically and the narrative has to be eked out of "potted" histories made in late antiquity.