History of the Peloponnesian War by Thucydides

Generally agreed to be the first of its kind, Thucydides’s history covers the war between Sparta and Athens, and though its accuracy remains moot – Thucydides was an Athenian general and so likely to be selective in his emphasis – it is an astonishing, rich and detailed drama to which historians return again and again.

The History of the Decline and Fall of the Roman Empire by Edward Gibbon

"History is little more than the register of the crimes, follies, and misfortune of mankind,” Gibbons wrote in this classic history tracing the Roman Empire from the 1st Century BC to the 15th AD. Vast, learned, opinionated, and witty, it is an absolute epic....