The Synopsis historion provides one of the only political narratives for later tenth and early eleventh- century history. It covers the period from 811– 1057 and survives in nine manuscripts. The text is a compilation of selections from older histories, sometimes copied word for word, sometimes with deletions or embellishments by Skylitzes. It was composed in the late eleventh century. The text is a narrative of political and military history focusing on the lives and choices of emperors, revolts, and occasionally ecclesiastical politics.

The Synopsis opens with a prologue in which the author criticizes much of recent Byzantine historical writing, which he accused of being too focused on recent events, too rooted in personal prejudices, and lacking in detail and factual accuracy. Instead, Skylitzes praised the work of George the Synkellos and Theophanes Confessor. He claimed that he would omit passages from his sources that he believed contained more emotion than fact. In the prologue, Skylitzes names fourteen histories that he used as sources for his own. Most of these texts have not survived. It cannot be confirmed that he used all of these, and he may have relied on other sources that he does not mention explicitly.

Scholars have worked to understand the sources Skylitzes used because some may have been more contemporaneous with the events they describe. Demetrios Polemis and several other historians have questioned whether some of Skylitzes's statements were invented by the author, rather than derived from now- lost sources.

Skylitzes based his account of the reign of Romanos Lakepenos on the third part of Theophanes Continuatus (known as Text III or Book VI). Since this text survives, we are able to compare it to Skylitzes to see how he adjusted his source. The result of this analysis shows that Skylitzes omitted precise details and minor characters in order to streamline the plot and heighten the drama of the particular episode.