Mohammed reported his first vision in the year 610. By 640, his followers had a small, growing empire. Before we trace this explosive growth, let’s look at the world that the Muslims challenged.
The map of Europe in 600 shows mostly scattered tribal homelands, with a few exceptions. If you look at the island of Britain, you can see that the Anglo-Saxons have begun to settle, but for the most part they’re only on the coast, in Kent (Cantware, they called it; here, Cantia). The Frisians, Saxons and Jutes are mostly still on the continent. The Picts, the original residents of Northern Europe, have already been pushed into the margins by the previous invasion of Celts. You can see the Picts only in the north of Scotland, while most of the two islands has Celtic labels. Over the next century, the Angles, Saxons and Jutes will push the Celts into the margins where they’ll merge with the dwindling Picts, but it hasn’t really happened yet.
The Celts in Britain are Christians, but by 600, the Roman Empire’s outposts are ruins. Hadrian’s Wall still runs across the north, marking where the Picts used to carry out raids a few centuries earlier. Some Roman roads are still in working condition, but the buildings at Bath and other settlements are lending building blocks to Celtic projects as they crumble.
The Celts themselves were pushed to the margins of the European continent by Franks. Frankia is one of the largest zones in 600; by this time, the Frankish kings have been ruling since Clovis united them by conquest in 481. In 600, the dynasty is still strong; Chlothar II began ruling as a young teenager. The Franks are officially Christians, converted by Latin missionaries.
Spain is dominated by Visigoths, a related tribe. King Reccared I converted to Catholic Christian (the Visigoths had been previously converted by Arian Christians) as the original Gothic language was dying out. After this time, Catholic bishops held much of the political power, including the right to select a king, whose capital was at Toledo.
The remnants of the Roman Empire are scattered around the eastern rim of the Mediterranean. Since the Goths came to Rome, much of Italy has been settled by Goths or Huns (Attila the Hun fought against Goths). Roman roads are definitely still functioning, as are Roman baths and aqueducts. Many of the towns continue to rule themselves by Roman customs, too. The invading Goths had a weaker culture than the Romans, so apart from names, most Gothic words are no longer used. (The exact opposite happened with the invading Anglo-Saxons in Britain.) Rome is “ruled,” to the extent that it is, from Constantinople. The rule becomes much more effective as you get closer to the city itself, and merchants would tell you the taxes are quite real and very heavy. Constantinople is opulent, crowded, and deep in its “Byzantine” period of kings poisoning each other. Craftsmanship is very fine: silver, gold, jewels, embroidery, painting and sculpture.
To the east of the Byzantine-controlled lands, there is a vast Persian empire. The inhabitants call their Sassanid-ruled land Eran; they are Zoroastrians who worship fire (more or less—let’s not get into theology). Persia is also a place of fine crafts and learning, like Constantinople. In particular, around this time they developed the art of making soft rugs covered with flowers. Persia gets its silk from trading with China, but has a rich vein of minerals to mine.
The first wave of Huns were absorbed into the Goths, and their related tribe, the Avars, have settled at the margins of the map. The large white areas of Eastern Europe are No Man’s Land, occupied by migrants and ruled by no central power.
And far to the south, Arabia is populated by pagan Arabs, with some Byzantine Christians and a strong presence of Jews.