Dorothea Jordan was an Irish

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

 actress, courtesan

Courtesan

A courtesan was originally a female courtier, which means a person who attends the court of a monarch or other powerful person.In feudal society, the court was the centre of government as well as the residence of the monarch, and social and political life were often completely mixed together...

, and the mistress

Mistress (lover)

A mistress is a long-term female lover and companion who is not married to her partner; the term is used especially when her partner is married. The relationship generally is stable and at least semi-permanent; however, the couple does not live together openly. Also the relationship is usually,...

 and companion of the future King William IV of the United Kingdom

William IV of the United Kingdom

William IV was King of the United Kingdom of Great Britain and Ireland and of Hanover from 26 June 1830 until his death...

, for 20 years while he was Duke of Clarence. Together they had ten illegitimate children, all of whom took the surname FitzClarence

FitzClarence

Fitzclarence or FitzClarence is an Anglo-Norman name originally meaning "son of Clarence" - it usually refers to a bastard son of a Duke of Clarence, or a descendant thereof, and was used by them as a surname...

.
She was born Dorothea (sometimes called Dorothy or Dora) Bland near Waterford, Ireland, the daughter of Francis Bland (d. 1778) and his mistress, Grace Phillips.