She was actively involved in politics and economy of her times, independently administering large feudal fiefdoms and taxes, and was instrumental in creating the famous royal Order of the Dragon.

Barbara was engaged in 1405 to Sigismund of Bohemia, King of Hungary, the youngest son of Charles IV, Holy Roman Emperor.

In 1409, Barbara gave birth to a daughter, Elizabeth, Sigismund's only surviving issue and heiress, who married King Albert II of Germany.

Barbara fell on her knees begging for the king's forgiveness but Sigismund refused to listen, until the 10-year-old Elizabeth intervened on behalf of her mother.

A notable feature was that the highest offices were now occupied by simple knights, instead of illustrious barons, like what had happened in the time of the Angevin rulers and Mary.

On 13 October 1431, Barbara sent a letter to the city of Košice, in which she informed them about loss of Likava and gave the order that their military divisions should be incorporated to her army as soon as possible.

[7] Mark Whelan notes that as the Roman queen, Barbara, through correspondence with Vienna or the Teutonic Order, was able to secure construction expertise (that she needed for her fortresses) from her German subjects, who provided a "far richer base of skills" than what she could find in the Hungarian kingdom.

He was especially shocked that "merchant's wives, various bawds, and people without important positions" came to see the queen and left her apartment freely, in a way impossible in the French court.

"[11] Days before the death of her gravely ill husband on 9 December 1437 at Znojmo, as a pretext to confiscate her large fiefdoms in the Hungarian kingdom (where she rivaled the king himself in number of fiefdoms and castles), she was quickly accused by her son-in-law Albert II of Germany of the Habsburg dynasty and his chancellor Kaspar Schlick of plotting against Sigismund, for which she was swiftly transported to prison in Bratislava castle and later forced to relinquish most of her possessions, including her dower.

She seems to have retreated from political life, although the Habsburg court saw her as dangerous and tried to accuse her of heresy, alchemy, and immoral and agnostic behavior, for which she received the sobriquet "Messalina of Germany".

Historians pay more attention to her independent character, her notable political achievements, her shrewd administrative of her property, her versatile nature (she spoke several languages and was a practicing alchemist).

[14][18] Recent research, such as those of Rolanda Fugger Germadnik ("the leading Slovene expert on Barbara of Cilli") or Daniela Dvořáková, aims at clearing the queen's name of the old disreputable accusations.

[19][20] Dvořáková opines that Barbara "ranks among the most fascinating female historical figures of the first half of the 15th century", although until now she has been in the shadow of her more celebrated husband.

Thanks to her wealth, multiplied by good management, a well-thought-through financial policy, as well as the choice of capable people, the queen always had money available, which her husband always needed.

[24] Machilek praises Dvořáková's work for successfully portraying Barbara as a gifted, self-confident ruler who displayed a non-conformist attitude in her widowhood.

Jörg K. Hoensch though does point out that during the period of 1416–1419, when Barbara was forced to govern alone without the other two members (Garai and Kanizsai) of the regency council (Regentschaftsrat) that Sigismund appointed when he left Hungary, she was unable to cope with the situation.

Gemahlin Sigismunds und ungarische Königin for an updated portrait, in which the author defends the queen from clichés but does not leave the ruling couple's action uncriticized.

[29] On the turbulent events happened before and after Sigismund's death, Roitner opines that it is hard to determine who was the person that ordered Barbara's arrest as well as her specific ambitions during that period.

[31] According to Stanislav Južnič, Barbara – the richest female alchemist of all times – used very expensive but easily breakable tools for her experiments, thus today there is not much hope of obtaining a preserved specimen.

For example, the German knight Johannes de Wallenroth (whose involvement with Barbara is written down by the Bavarian historian Enoch Widmann, who lived two centuries after Barbara) actually served in her court and possibly later boasted about the queen's favour when he retired to Germany, but it is hard to imagine that Sigismund would tolerate him to the degree that he could continue to work for her many years after the alleged uncovering of infidelity.

During a time when royalty in both western and eastern Europe could barely sign their names, Barbara knew German, Hungarian, Czech, Latin, and even a little Polish.

In fact, Barbara appears to have been an early example of an emancipated woman, who probably frightened her male contemporaries and led to her nefarious reputation as a lesbian vampire.