It may be an uncomfortable fact, but Anglo Saxons and the Viking races thought that slavery was a normal part of their working economy. It has been estimated from entries in the Doomsday Book that as much as 10% of the population of Anglo Saxon England were slaves, although this is difficult to verify, as one has to make an estimate of the size of slave families from the actual working slaves listed. The general Old English term for a slave was wealh, which is associated with the ideas of 'Welsh' or 'foreigner.' That gives a clue to one of the major sources of slaves: prisoners of war.

Slaves may have worked at ploughing, building walls, spreading muck, peat digging, grinding corn, dairy duties cooking or general housework. However, higher status occupations are recorded, such as goldsmith or embroiderer. Some female slaves were used as sex workers, although later laws tried to protect female slaves from sexual abuse.

Giving up one's slaves (sometimes known as manumission) may have been hard to contemplate: who else was going to plough the fields, cook, or herd the pigs, whist the landowner got on with higher status tasks like weaving, trading or warfare?

There were a few other ways that people may end up as slaves, other than as prisoners of war: the Old English term wite þeow refers to penal enslavement i.e. a punishment of a court for crime. Some families who had become bankrupt may sell their children, or even themselves to ensure survival, and in some cases they were allowed to earn money to redeem themselves, and repay their price or debt.

The term that Vikings used for slavery was generally ánauð, and a slave was referred to as a þral or thrall. One could be termed a fostne, which indicated that you were a hereditary fostered slave. Bond servants (bondi) could pay off their owner if they could raise enough money. The image of a slave was one who had short cropped hair and an iron neck collar. After Christianisation a female slave was not allowed to wear a kerchief over her hair, which was a privilege reserved for her mistress.

Dublin was to become the centre for the slave trade for the Vikings in Ireland, with Bristol being an important exit port even then, well before the African slave trade centuries later. They probably also used Jorvik (York) and London as trading centres.