Bona Sforza was one of the most remarkable women of Renaissance Europe. Born into one of Italy’s leading ruling families and connected to figures such as Lucrezia Borgia through the tangled politics of Italian dynasties, she became queen consort of Poland and grand duchess of Lithuania.
More than a royal bride, she brought to Poland the administrative, financial and cultural ideas of Renaissance Italy. She understood how wealth, land and government could be used to strengthen a dynasty.
Although never a reigning monarch, Bona became one of the most politically influential women ever to sit on the Polish throne. Admirers praised her intelligence and determination. Critics condemned her as ambitious, overbearing and dangerously powerful. That tension lies at the heart of her story.
The debate over Bona’s legacy raises a question that still resonates today: why are women who wield power effectively so often judged differently from men who do the same?
Training for greatness
Bona Sforza, born in 1494, was the daughter of the Duke of Milan. She arrived in Poland in 1518 as a royal bride of Sigismund I. Contemporary observers praised her intelligence, learning and virtue, qualities they described as “rare among maidens”.
Bona grew up in Bari, Italy. Her mother, Duchess Isabella of Aragon, ruled the duchy of Bari in her own right. She exercised authority with confidence. Isabella ensured that Bona received a humanist education in languages, history, law, moral philosophy and public speaking, preparing her not simply to marry well, but to govern.
Bona’s tutors shaped her view of the world and of herself. They instilled in her the belief that she was “born to rule”, preparing her to see leadership not as a privilege, but as a responsibility.
Government required judgement, alliances and financial skill.
Bona learned to treat land as a working system of connected parts: fields, forests, tenants, mills, markets, workers and, of course, taxes.
Bona used this knowledge to strengthen the Jagiellon dynasty, the ruling family of Poland and Lithuania. She treated royal lands as productive assets, recovering estates that had been lost, leased or mortgaged by earlier rulers.
By 1555, alongside the lands assigned to her as queen, she controlled the revenues of 15 royal towns and 191 villages.
The result was greater dynastic wealth and greater independence and leverage in the royal house dealings with powerful nobles.
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Land reforms
Bona’s reforms focused on making royal lands more productive and their revenues more reliable. She recovered lost Crown property, improved record-keeping, and insisted that surveys and legal decisions be documented and enforced.
She also promoted economic development through new settlements, markets, transport links and local infrastructure. These measures increased trade and created new income for the royal family.
Accused of poisoning rivals
Yet the more successful Bona became, the more criticism she attracted. Male nobles did not simply say they opposed higher taxes or the consolidation of the royal domain. They often framed her authority as unnatural.
One of the powerful courtiers, Krzysztof Szydłowiecki, put it bluntly in 1527: “nothing happens without her will”.
Her success provoked fierce opposition. During the Lwów rebellion of 1537, nobles accused Bona of greed, overreach and wielding too much influence. Some complained that earlier queens had no role in government, but under Bona, “everything happens differently” because she had “as much power as she wishes”.
Queens were expected to be wives, not political actors. Yet powerful men also accumulated land, built networks and influenced government and church appointments without attracting the same criticism.
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After her death in 1557, Bona’s reputation darkened. She was accused of poisoning rivals, practising witchcraft, manipulating politics and corrupting government. Some accusations grew from real political conflicts, but others reflected discomfort with a woman who exercised power so effectively.
Her recovery of royal lands threatened powerful nobles. Critics recast her competence as greed, her authority as overreach, and her political skill as dangerous ambition.
Women in leadership face familiar criticism
Like Bona, women leaders today are still often judged by standards that men rarely face.
A United Nations report on corporate leadership found that across 20 advanced economies, women held only 6% of chief executive officer roles, 7% of board chair roles, and 15% of chief financial officer roles.
Women’s access to capital is another parallel. A report from the Organisation for Economic Co-operation and Development (OECD) on women entrepreneurs found that, in 2024, women were about half as likely as men to report borrowing from a bank to start, run or expand a business. A US report on venture capital funding for tech companies shows progress, with female-founded companies raising a record amount. But the debate continues because access to investment remains uneven.
Modern attitudes to women also matter. A Stanford University institute describes the “likeability penalty”: women leaders who appear competent and assertive can be judged as less likeable, while men often receive praise for similar behaviour.
Five centuries later, the pattern remains familiar. Bona’s wealth, discipline and confidence strengthened the monarchy. They also made her a target. They made her easier to attack.
The question her life leaves us with is simple: when women manage power well, do societies recognise leadership, or do they still call it ambition?
