The earliest source that mentions her is the will of her maternal great-grandmother Jelena Lazarević, dated 25 November 1442, in which she left her her gold earrings and a snake-shaped bracelet.

[2] Stjepan was a member and significant supporter of the Bosnian Church, while her mother was an Eastern Orthodox Christian; Catherine was raised in her father's confession.

The Catholic Church did not recognize his union with Vojača as a valid marriage, and Pope Eugene IV gave him permission to repudiate her in early 1445.

[9] The new queen consort converted to Catholicism ("laid aside Patarin errors"), likely prior to her marriage,[7] and was allowed by Pope Eugene to choose for herself two chaplains from among Bosnian Franciscans.

[10] The Queen's father appears to have contemplated converting too, but eventually gave up the idea and remained an adherent of the Bosnian Church until his death.

In December 1458 she wrote to Pope Pius II to request that the church in Jajce, built along with a Franciscan monastery and a vicariate, be named after her namesake, Saint Catherine of Alexandria.

Pius conceded her request in a bull issued on 13 December, granting absolution to anyone who visited Queen Catherine's church at Christmas or Easter, or on certain feast days.

[10] Catherine's relations with him were poor during Thomas's lifetime; this now threatened to weaken the kingdom against its adversaries, most of all the rapidly expanding Ottoman Empire.

[10] Having assured himself of Stephen Tomašević's "affection" for his daughter, the Grand Duke refrained from disputing the succession and claiming the crown for his grandson by Catherine.

[15] Although popularly believed to have retired to the castle of Kozograd above Fojnica as dowager, there is no historical basis for dismissing the possibility that she remained at the royal court in Jajce as the mother of Stephen Tomašević's closest heirs.

The Grand Duke and the King started preparing defenses, but the latter made a fatal mistake by provoking the powerful enemy further and then relying on the help of Christendom.

The Queen rode to Konjic and from there probably towards Drijeva, before finally embarking on the promised vessels in Ston and sailing to Lopud, an island held by the Republic of Ragusa.

In Dubrovnik, Queen Catherine attempted to claim the tribute of Ston, paid annually to Bosnian rulers, but the authorities declined on 20 August.

On 26 October, Catherine entrusted Ragusa with Thomas's silver sword, stipulating that it should be handed over to Sigismund "should he ever be freed"; or else to nobody but the person she would name as heir.

Her presence at the proxy wedding of Grand Prince Ivan III of Russia and the Byzantine princess Sophia Palaiologina in 1472 was widely noted, as was her pilgrimage to L'Aquila on the occasion of the translation of Bernardino of Siena's relics to a new church (the construction of which was funded, among others, by King Thomas).

That she lived a comfortable life can be deduced from the impression she left on Roman chroniclers, who wrote about the entourage of 40 mounted knights accompanying her on a pilgrimage to St. Peter's Basilica to celebrate the new year 1475.

Intent on finding a proxy for negotiations with the Sublime Porte, as well as obtaining resources for their release, she turned to Ludovico III Gonzaga, Marquis of Mantua, on 23 July 1470.

[31] On 11 February 1474, she addressed a letter to the Duke of Milan, Galeazzo Maria Sforza, asking him to help her reach the Ottoman border and enter negotiations.

[31] Disappointed at the failure, Catherine returned to Rome and entered the Secular Franciscan Order, probably inspired by a monk at the Basilica of Santa Maria in Ara Coeli.

Considering herself entitled to dispose of the Bosnian crown, she named Pope Sixtus IV and his successors guardians of the kingdom, obligating them to enthrone her son should he convert back to Christianity or else her daughter should she reconvert.

She decreed that, if her son never returned to the Christian faith, King Thomas's silver sword left in Dubrovnik for safekeeping should be handed to her nephew by Vladislav, Balša Hercegović.

[37] The cult of Queen Catherine, who was first mentioned as beatified in the Paris-published Martyrologium franciscanum in 1638,[33] originated in the Franciscan province of Bosna Argentina during the Ottoman rule.

Following the Ottoman conquest, a majority of Bosnians converted to Orthodoxy or Islam, and the Franciscans started promoting Catherine as a symbol of Bosnia's statehood and of its pre-Ottoman Catholic identity.

[39] The life of Queen Catherine has been one of the most popular themes in the history of Bosnia and Herzegovina, attracting the attention of scholars from the neighbouring countries of Croatia and Serbia as well.

[38] Due to her association with both of its eponymous historical regions, as well as her personal and close familial ties to Catholicism, Eastern Orthodoxy, Bosnian Christianity and Islam, Queen Catherine is increasingly becoming an important state symbol in Bosnia and Herzegovina.

The political and religious leaders of the third group, Orthodox Serbs, also tend to claim Bosnian medieval history as exclusively their own but have not yet shown significant interest in Catherine herself.