Helena Palaiologina (Serbian: Јелена Палеолог Бранковић; 1431 – 7 November 1473) was a Byzantine despotess of Serbia as the wife of Despot Lazar Branković, who ruled from 1456 until his death in 1458. Together they had three daughters.
Helena was the eldest daughter and child of Thomas Palaiologos, Despot of the Morea.
After Smederevo fell to the Ottoman Turks on 20 June 1459, Helena left Serbia and fled to the Greek island of Leukas where she converted to Catholicism. She later became a nun, assuming the name of Hypomone (Хипомона, meaning "Patience").
Helena was born in the Despotate of the Morea in 1431, the eldest daughter and child of Thomas Palaiologos, Despot of the Morea and Catherine Zaccaria of Achaea. She had two younger brothers, Andreas Palaiologos and Manuel Palaiologos, and a sister, Zoe, who would become the wife of Ivan III of Russia. Her maternal grandparents were Centurione II Zaccaria and Creusa Tocco. She had a first cousin, Helena Palaiologina, who became Queen consort of Cyprus.
Marriage and issue
In October 1446 she was sent to Serbia, where in Semendria, she married Lazar Branković, son of Lord Đurađ Branković. The Masarelli Vatican Manuscript records the marriage of Lazar to the daughter of Despot Thomas Palaiologos. On 24 December 1456, Helena became Despotitsa of Serbia when Lazar succeeded his father to the despotate. They had three surviving daughters:
Jelena Branković (upon her marriage she changed her name to Maria) (1447–1498), married King Stephen Tomašević of Bosnia, by whom she had issue; she may have later entered the harem of a Turkish general.
Milica Branković (died 1464), married Leonardo III Tocco, Ruler of Epirus, by whom she had one son; she died in childbirth.
Jerina Branković, married John Kastrioli, by whom she had issue.
De facto ruler of Serbia
When her husband died after just over one year of rule, the Grand Vojvoda Michael Andjelovic was chosen to lead a council of men, becoming the de facto ruler of Serbia. Helena, together with her brother-in-law, Stefan Brankovic, made a bid to seize power. She got her opportunity shortly afterwards in March 1458 when the Ottomans invaded Smederevo, and local rebel Serbs took Michael Andjelovic prisoner. Helena and Stephen assumed control as joint de facto rulers of Serbia. In order to strengthen her position, she sought an ally in King Stephen Thomas of Bosnia, and personally arranged a marriage between his eldest son, Stephen Tomašević and her eldest daughter, Helena, on 1 April 1459. On 20 June 1459, the Ottomans launched a major assault against Smederevo and succeeded in taking the city, which effectively brought an end to Serbia as a despotate. Helena was compelled to leave Serbia, and along with her two unmarried daughters sought refuge on the Greek island of Leukas, where she converted to Roman Catholicism and took the veil as Hypomone. She died there on 7 November 1473 at the age of 42.