Interracial marriage
From AD 839, Viking Varangian mercenaries who were in the service of the Byzantine Empire, notably Harald Sigurdsson, campaigned in North Africa, Jerusalem and other places in the Middle East during the Byzantine-Arab Wars. They interbred with the local population as spoils of warfare or through eventual settling with many Scandinavian Viking men taking Arab or Anatolian women as wives. There is archaeological evidence the Vikings had established contact with the city of Baghdad, at the time the center of the Islamic Empire, and connected with the populace there. Regularly plying the Volga with their trade goods (furs, tusks, seal fat, seal boats and notably female slaves; the one period in the history of the slave-trade when females were priced higher than males), the Vikings were active in the Arab slave trade at the time. These slaves, most often Europeans that were captured from the coasts of Europe or during war periods, and sold to Arabic traders in Al-Andalus and the Emirate of Sicily.
Kingdom of the Isles
Prior to the Viking incursions the southern Hebrides formed part of the Gaelic kingdom of (or Dalriada). North of , the Inner and Outer Hebrides were nominally under Pictish control although the historical record is sparse. According to Ó Corráin (1998) "when and how the Vikings conquered and occupied the Isles is unknown, perhaps unknowable", although from 793 onwards repeated raids by Vikings on the British Isles are recorded. "All the islands of Britain" were devastated in 794 with Iona being sacked in 802 and 806. Various named Viking leaders, who were probably based in Scotland, appear in the Irish annals: in 837, in 845 and in 847. Another early reference to the Norse presence in the Irish records is that there was a king of "Viking Scotland" whose heir, , took an army to Ireland in 848.