400s (decade)

The 400s refers to the decade spanning the years 400 to 409 inclusive. This period falls within the Early Middle Ages, specifically the Late Antiquity period, marking a transition between the Roman Empire and the emerging medieval kingdoms. Key events and developments during this decade varied significantly depending on the geographical region.

In Western Europe, the Western Roman Empire was facing increasing pressure from Germanic tribes. The Visigoths continued their westward migrations, eventually establishing a kingdom in southwestern Gaul. Other Germanic groups like the Franks and Burgundians were also consolidating their power. The Roman military presence in Britain was weakening, allowing Anglo-Saxon settlers to gain a foothold.

In the Eastern Roman Empire (Byzantine Empire), relative stability was maintained under Emperor Arcadius, although challenges persisted in the form of internal political rivalries and external threats from the Huns.

Elsewhere, the Sasanian Empire in Persia continued to be a major power, vying for influence in the Middle East and Central Asia. In India, the Gupta Empire was flourishing, considered a golden age for Indian science, art, and literature.

Culturally and religiously, Christianity was becoming increasingly dominant in the Roman world, though pagan traditions still persisted. Doctrinal controversies within the Church continued to be debated and addressed.