Prince Peter of Greece and Denmark was a Greek prince, soldier and anthropologist specialising in Tibetan culture and polyandry. Born in Paris and high in the line of succession to the Greek throne, Prince Peter was deemed to have forfeited his succession rights by marrying a twice-divorced Russian commoner, Irina Aleksandrovna Ovtchinnikova. Following his first scientific voyage to Asia, Peter served as an officer of the Greek army during the Second World War. The Prince returned to Asia several more times for his research of Tibetan culture. He strongly protested against the royal family's treatment of his wife. After King Paul's death, he declared himself heir presumptive to the Greek throne, on the pretext that female dynasts had been unlawfully granted succession rights in 1952. Peter eventually separated from his wife and died childless in London.

The currently deposed Greek royal family was the ruling family of the Kingdom of Greece from 1863 to 1924 and again from 1935 to 1973. The family is a branch of the Danish royal family, itself a branch of the House of Glücksburg. Upon its accession to power, It replaced the House of Wittelsbach that previously ruled Greece from 1832 to 1862. The first monarch was George I of Greece, the second son of King Christian IX of Denmark. The current head of the family is Pavlos, who assumed the role upon the death of his father, former King Constantine II on 10 January 2023.