Baldwin I was the first Emperor of the Latin Empire of Constantinople; Count of Flanders from 1194 to 1205 and Count of Hainaut from 1195 to 1205. Baldwin was one of the most prominent leaders of the Fourth Crusade, which resulted in the sack of Constantinople in 1204, the conquest of large parts of the Byzantine Empire, and the foundation of the Latin Empire. He lost his final battle to Kaloyan, the emperor of Bulgaria, and spent his last days as his prisoner.

The Latin Emperor was the ruler of the Latin Empire, the historiographical convention for the Crusader realm, established in Constantinople after the Fourth Crusade (1204) and lasting until the city was reconquered by the Byzantine Greeks in 1261. Its name derives from its Catholic and Western European ("Latin") nature. The empire, whose official name was Imperium Romaniae, claimed the direct heritage of the Eastern Roman Empire, which had most of its lands taken and partitioned by the crusaders. This claim however was disputed by the Byzantine Greek successor states, the Empire of Nicaea, the Empire of Trebizond and the Despotate of Epirus. Out of these three, the Nicaeans succeeded in displacing the Latin emperors in 1261 and restored the Byzantine Empire.