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.
Ímar
The earliest recorded Viking raids in Ireland occurred in 795. Over time, these raids increased in intensity, and they overwintered in Ireland for the first time in 840–841. In 841 a longphort was constructed at (Irish for "hurdled ford"), a site which would later develop into the city of Dublin. Longphorts were also established at other sites around Ireland, some of which developed into larger Viking settlements over time. The Viking population in Ireland was boosted in 851 with the arrival of a large group known as "dark foreigners" – a contentious term used to refer to the newly arrived Vikings, as opposed to the "fair foreigners", i.e. the Viking population which was resident in arrival prior to this influx. A kingdom in Viking Scotland was established by the mid ninth-century, and it exerted control over some of the Vikings in Ireland. By 853 a separate kingdom of Dublin had been set up which claimed control over all the Vikings in Ireland.