More detail for the whole period is provided by Plutarch, in his biographies of Themistocles, Aristides and especially Cimon. Plutarch was writing some 600 years after the events in question, and is therefore a secondary source, but he often names his sources, which allows some degree of verification of his statements. In his biographies, he draws directly from many ancient histories that have not survived, and thus often preserves details of the period that are omitted in Herodotus and Thucydides's accounts. The final major existing source for the period is the universal history ("Bibliotheca historica") of the 1st century BC Sicilian, Diodorus Siculus. Much of Diodorus's writing about this period is drawn from the much earlier Greek historian Ephorus, who also wrote a universal history. Diodorus is also a secondary source and often derided by modern historians for his style and inaccuracies, but he preserves many details of the ancient period found nowhere else.