A sentence from Burckhardt’s description of the Persian campaigns of Galerius: “But two indecisive battles and a third which Galerius lost through excessive boldness again drenched with Roman blood the desolate plain between Carrhae and the Euphrates where Crassus had once led ten legions to their death.”

What does one need to know to write a sentence like that? A great deal. Burckhardt gives us judgments about three battles in the space of half a sentence (two indecisive, one lost); he tells us the cause of Galerius’s loss in the third battle; he knows that the battle was a Roman disaster (the ground is “drenched” with blood); he knows the geography of ancient Persia, that there is a desolate plain between the town of Carrhae and the Euphrates; and he knows that this was also the site of a bloody Roman defeat in the first century BC, in another Persian campaign led by Marcus Licinius Crassus.

In short, Burckhardt packs what would be several weeks of research for a normal historian into a single succinct sentence.