Boris Johnson has ancestors from Turkey, France and the US
18 December 2008. A total of 30 million Brits have foreign ancestors, with 23% originating from Ireland, 10% from France, 9% from Germany, 6.5% from Scandinavia and 5% from Canada.
Online records have uncovered several celebrities with foreign roots.
London Mayor Boris Johnson has ancestors from Turkey, France and the US.
Victoria Beckham counts 19th century German immigrants among her ancestors.
Actress Helen Mirren, who played The Queen, is descended from Russian noblemen.
As the world celebrates International Day of Migrants today,the social history website Ancestry.co.uk revealed that 84% of Britons admit they know nothing about their immigrant ancestry.
Despite being unaware of their immigrant ancestry, Britons nonetheless practice a variety of foreign traditions over Christmas.
Decorating the Christmas tree is a German custom for example, while eating Christmas Turkey is American, and kissing under mistletoe is a Scandanavian tradition.
The research also found that Brits celebrate 12 other holy festivals in December as well as Christmas, including Jewish festival Hanukkah and Muslim festivals Eid al-Adha and Waqf-al-Arafa.
Ancestry.co.uk spokesman Dan Jones said: "So much of Britain’s cultural and political history stems from its immigrant heritage, which makes it even more staggering when we learn how few of us are actually aware of our foreign ancestry. "For many families, Christmas is the one time in the year when they all come together, which explains why it’s one of the most active periods for family history research. If there are rumours in your family of foreign ancestry, this could be the perfect time to find out more about them."