The British royal cousin marriages are considered an example of endogamy, or the practice of marrying within a specific class and social group, often for financial gain or influence in affairs of state. The handful of first-cousin marriages was not out of the norm for their time.

Unknown family relationship

After the 11th century, in only two cases (those of the first wife of James II and of Edward VIII) is there no known familial relationship. Neither woman was queen consort (one died before her husband became king, and the other married after he abdicated). Both marriages were considered scandalous for their time. The first wife of James II was the only daughter of a wealthy man, but with no pedigree. The marriage did produce two future sovereign queens. Edward VIII married Wallis Simpson, and cited his desire to marry the twice divorced American woman as the reason for his abdication in 1936.

First cousin marriages

Richard III was portrayed by Shakespeare in Act IV, scene III of the play, "Richard III," as planning to murder his present wife, Anne Neville, and plotting to marry his teenage niece, Elizabeth of York, and stop the Wars of the Roses. However, this proposed marriage seems to have been a rumor that Shakespeare used to make Richard III seem particularly evil, and there have been no marriages in British royalty closer than first cousin.

The monarchy of the United Kingdom, commonly referred to as the British monarchy, is the constitutional monarchy of the United Kingdom and its overseas territories. The monarch's title is "King" (male) or "Queen" (female). The current monarch and head of state, Queen Elizabeth II, ascended the throne on the death of her father, King George VI, on 6 February 1952.

The monarch and his or her immediate family undertake various official, ceremonial, diplomatic and representational duties. As the monarchy is constitutional, the monarch is limited to non-partisan functions such as bestowing honours and appointing the Prime Minister. The monarch is, by tradition, commander-in-chief of the British Armed Forces. Though the ultimate formal executive authority over the government of the United Kingdom is still by and through the monarch's royal prerogative, these powers may only be used according to laws enacted in Parliament and, in practice, within the constraints of convention and precedent.