Latinate form of Isabel. This name was borne by many medieval royals, including queens consort of England, France, Portugal, the Holy Roman Empire and Hungary, as well as the powerful ruling queen Isabella of Castile (properly called Isabel).In the United States this form was much less common than Isabel until the early 1990s, when it began rapidly rising in popularity. It reached a peak in 2009 and 2010, when it was the most popular name for girls in America, an astounding rise over only 20 yea...