What ethnicity was Isaac Newton?

Sir Isaac Newton was an Englishman of Caucasian ethnicity. The name "Newton" is a contracted version of "new town." His mother's maiden name is Ayscough, which dates from before the Norman Invasion and originates from county Cumberland.

There has been speculation that Sir Isaac Newton was of Jewish ancestry. Little is known of his father, who died before Newton's birth, but given his mother's ethnic background, such speculation seems unfounded. Jewish presence in England was nominal given the expulsion of an already depleted English Jewry in 1290 under King Edward I. Jews in England were few and in hiding for the most part after 1290 and up until Newton's birth in 1643.