In the words of historian Donald Nicol, "Mara Brankovic was one of the most remarkable products of the melting pot of ruling families that banded together for survival in the Balkans during and after the Turkish conquest of the Byzantine Empire in the fifteenth century."
Born around 1416, she was the eldest daughter of Durad Brankovic, whom had been anointed Despot of Serbia in 1429 by Emperor John VIII but who ruled under sufferance of the Sultan. He played a hazardous game, pretending to be their faithful vassal while trying to build up a Christian coalition against the Turkish tide. He built the fortress of Smederevo on the Danube near Belgrade, the last capital of medieval Christian Serbia.
Nicol states that Mara's mother was the sister of the Trebizond Emperor, John Komnenos, however he does not attribute a source for this and it appears unlikely for a number of reasons, the main being that there is no record of a Komnenos princess marrying a Serbian Despot from the Trebizond records or any mention of it in other sources.
The more commonly given genealogy for Mara's mother is Eirene Kantacuzenos, of the Byzantine noble family. She is named as the mother of Brankovic's other children. Their marriage is recorded as being in 1414.
One feature of Durad's reign was the increasing number of Byzantines at his court. Partly this was due to his marriage to a scion of the Kantacuzenoi but in addition, the fall of Thessaloniki in 1430 saw a huge influx from that region, the Kantacuzenoi heartland. Mara's Kantacuzenoi uncle, Thomas, was in command of Durad's army for much of his rein and in 1457, during the quasi-civil war that followed Durad's death, Thomas was in Mara's entourage that sought shelter at the Ottoman court. He was still among her household when he died in 1463. It is through this enduring Kantacuzenoi influence that Mara's link to the Byzantine culture can be traced.
In 1431, Durad Brankovic concluded a peace treaty with Sultan Murad II by agreeing to give his eldest daughter as a bride. (Another reason the Nicol assertion is unlikely is that Mara would be nineteen based on his dates - rather old to be unmarried or to appeal to the Sultan in this sort of arrangement). The marriage took place in 1435 at which point Mara joined his three other wives in the harem. She bore him no children (he had 9 by his other wives) and rumours from the time held that the marriage was never consummated.
Mara appears to have had a close relationship with Murad's son, the future Sultan Mehmed II. Mehmed's own mother died two years before he came to the throne on a permanent basis in 1451 and throughout his reign he is recorded as showing special honour to Mara, his mother-substitute. She held the title of Valide Sultan, or Mother to the Sultan - a venerated position that made her top dog in the harem. She was also allowed to maintain her own estate at Daphni at the foot of the holy mountain of Mount Athos. She seems to have had a great deal of freedom of movement in the years following her husband's death, appearing in both Constantinople, Serbia and Daphni. From there she acted as a bridge between East and West and was instrumental in arranging peace talks between Venice and the Porte throughout the Long War. Her involvement in these diplomatic schemes seems quite remarkable for a woman in the 15th century. Clearly Mehmed valued her opinion but she is lauded as well by the state records of Venice. When peace finally did arrive in 1479, Mara played a full part in the go betweens.
Remarkably (but not uniquely - her Byzantine peers in the Persian court did likewise), Mara retained her Christian faith even after marriage. Furthermore, in the years following the conquest of Constantinople she became an active defender of the religious interests of the Greek Christian population. On several occasions she intervened to try and thwart corruption in the office of the Patriarchate. In 1466 Symeon successfully obtained the Patriarchal throne after he paid the Grand Vizier's faction 2000 pieces of gold. Mara was outraged by the simoniac action of Symeon, and she went to Constantinople to complain to Mehmed. In response to her requests, and to a donation by her of 2000 pieces of gold, the Sultan deposed Symeon and appointed to the Patriarchate the candidate of Mara, Dionysius. Similarly in 1474 the Holy Synod also accepted to pay an annual fee of 2000 florins to the Ottoman state - effectively putting the office of the Patriarch up for sale. On his return to Constantinople in early 1475, Symeon was outbid by Raphael I, probably supported & funded by Mara.
In 1459 the Sultan granted to Mara full possession of the Monastery of St Sophia in Thessalonica and all its revenues. Mara's Christian work extended to the recovery of Holy relics and their return to monasteries and churches in the west. In 1469 she arrange for the bones of John of Rila to be returned to Rila monastery. More controversially, In 1463, she is credited with the recovery of the bones of Luke the Evangelist from Bosnia to Venice. This was a pet project of the new Doge, Christoforo Moro who was rebuilding the church of San Giobbe and wanted the saint enshrined there. Embarrassingly, the Benedictine monks of Padua had been venerating bones of the same Saint Luke for centuries and they enacted a legal challenge to the veracity of the recovered relic. Later history seems to strengthen their case. The Padua relic was tested in recent years and showed them to be of the correct vintage to be the saint. If the San Giobbe bones were a fraud, did Mara know?
An unusual footnote to her history was the incident in 1451 when, newly widowed, she became briefly a candidate to wed the Byzantine Emperor Constantine XI. He had been married twice and lost each without producing an heir. The imperial advisors considered a number of ladies as suitable Empresses, possibly Anna Notaras among them. When Mara came on the matrimonial market, some thought she was the ideal choice. The matter was put to her father who welcomed the idea. It would have made Mara unique - the wife of both Sultan & Emperor. She firmly declined to have anything to do with the idea. She vowed to live a chaste and celibate life from the rest of her days but she did not - as was common for widows of her station - become a nun. She resisted another marriage proposal in 1454 from Jan Jiskra, the Czech mercenary captain who would arrest Vlad Dracula in 1463.
Mara died at Daphni in September 1487.