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.
Viking Age
The earliest date given for a Viking raid is 789, when according to the "Anglo-Saxon Chronicle", a group of men from Norway sailed to the Isle of Portland in Dorset (it was wrongly recorded as 787). They were mistaken for merchants by a royal official. When asked to come to the king's manor to pay a trading tax on their goods, they murdered the official. The beginning of the Viking Age in the British Isles is often set at 793. It was recorded in the "Anglo–Saxon Chronicle" that the Northmen raided the important island monastery of Lindisfarne (the generally accepted date is actually 8 June, not January):