Previously thought to be a portrait of Mary I, this is now generally accepted as a likeness of Margaret of Parma. There are several versions of this portrait in which the head is repeated but in which the sitter is differently dressed (for example a half-length version in the Philadelphia Museum of Art, attributed to Anthonis Mor). On grounds of costume, this portrait may be dated around 1560 and is thought to be a version painted soon after the original by Mor.

Margaret of Parma was the illegitimate daughter of the Holy Roman Emperor Charles V. She married Alessandro de' Medici, Duke of Florence in 1536 and, following his death, she married Ottavio Farnese, Duke of Parma in 1538. She was appointed Governor of the Netherlands in 1559 and retired to Italy in 1567. Accompanied by her son Alessandro Farnese, she visited the Netherlands and England during the winter of 1556-7. During that visit it is known that Alessandro sat to Anthonis Mor for a portrait, and it is possible that Margaret was painted by the artist on the same occasion.