Map of Europe in 900 AD (900 CE)

The Kingdom of the Franks, also known as the Frankish Kingdom or Francia, was the largest post-Roman kingdom in Western Europe. It was established by the Franks, one of the Germanic peoples.

Mapped extent in 900 CE: 1.18M km²

Kievan Rus', also known as Kyivan Rus', was the first East Slavic state and, later, an amalgam of principalities, in Eastern Europe from the late 9th to the mid-13th century. Encompassing a variety of polities and peoples, including East Slavic, Norse, and Finnic, it was ruled by the Rurik dynasty, founded by the Varangian prince Rurik.

Mapped extent in 900 CE: 990,104 km²

The Khazars were a semi-nomadic Turkic people who established a major commercial empire in the late 6th century CE spanning the south of modern European Russia, southern Ukraine, and western Kazakhstan. It was the most powerful polity to emerge from the break-up of the Western Turkic Khaganate.

Mapped extent in 900 CE: 749,635 km²

The Byzantine Empire, also known as the Eastern Roman Empire, was the continuation of the Eastern part of the Roman Empire centred on Constantinople during late antiquity and the Middle Ages. Having survived the fall of the Western Roman Empire in the 5th century AD, it endured until the fall of Constantinople to the Ottoman Empire in 1453.

Mapped extent in 900 CE: 635,046 km²

East Francia or the Kingdom of the East Franks was a successor state of the Carolingian Empire ruled by the Carolingian dynasty until 911. It was established through the 843 Treaty of Verdun which divided the former kingdom of Francia into three kingdoms: Francia Orientalis ; Francia Media ; and Francia Occidentalis.

Mapped extent in 900 CE: 522,040 km²

The Emirate of Córdoba, and from 929, the Caliphate of Córdoba, was an Arab Islamic state ruled by the Umayyad dynasty from 756 to 1031. Its territory comprised most of the Iberian Peninsula, the Balearic Islands, and parts of North Africa, with its capital in Córdoba.

Mapped extent in 900 CE: 406,844 km²