This week iconic pop star Britney Spears gave stirring and emotional testimony about living under the conservatorship granted to her father in 2008. Likening her experience to enslavement, Spears said she had been forced to work against her will, compelled to enter a mental-health institution, drugged, and prevented from having children. The shocking revelations drew instant support and raised questions about the nature of the conservatorship system. How could an international star who earned millions of dollars be exploited and controlled in this way?

For years the #FreeBritney movement led by fans of Ms. Spears has questioned the legality of the system. Conservatorship, sometimes known as guardianship, is a last-resort legal measure that is typically invoked on behalf of those with severe disabilities or dementia. Recent news coverage coupled with the release of films like I Care A Lot has shone a spotlight on the ways in which the system is open to abuse. Conservatorship has ancient roots and when you look at its history it’s unsurprising that socially marginal people—mostly the elderly and those with disabilities—are susceptible to this kind of legal manipulation. In fact, some might say that was always the point.

Conservatorship was born in ancient Rome. Roman law focused on the power and privileges invested in the pater familias (the citizen father and head of household), who were seen as the protectors of minors, their wives, and enslaved persons who lived in their home. Discipline began here: Roman law invested the pater familias with the power to administer punishment and justice within his own household. It was, University of Iowa ancient historian Sarah Bond told me, “quite literally the patriarchy” and “both the young and women were seen as vulnerable and often mentally incapable” of making their own financial decisions. If the father died, therefore, then a different male relative (usually an uncle) was appointed as a guardian (a tutor or curator). With a few exceptions, adult women as well as children needed the approval and support of their male tutor to take any kind of legal action of their own. Technically, their assets were the property of the tutor for as long as the tutelage continued.

It wasn’t just women and children who could find their legal and financial privileges revoked. As early as the fifth century BCE, when the Laws of the Twelve Tables, were formulated “diminished mental capacity” became a category in the legal system. A Roman magistrate, Bond told me, had the power to appoint a curator to oversee the finances of someone who was mentally incapable (potentially because of age) or a spendthrift. The assumption here, as in our own system, is that certain kinds of “bad” decisions render one incapable of making any decisions. Money and the preservation of wealth is often the key element. Implicit in this institution, as Bruce Frier writes in his Casebook on Roman Family Law, is a focus on “the protection of the ward’s property, mainly in the interest of potential heirs.” Even today it is mainly those with assets and money who are likely to find themselves in conservatorship.

The basis for this whole system, Bond said, was the power of the father as the supreme authority in the lives of women and children. The only way a woman could hope to gain any kind of personal legal status was through childbearing. The ius liberorum introduced by Augustus around the turn of the Era granted women who had had three children the opportunity to escape from the constant oversight of guardianship. For male children tutelage and curatorship ended when they became men in their teens, but could be extended until the age of 25. For female children it could continue in perpetuity.

This may seem to be 2,000 years and 5,000 miles removed from our own world, but the U.S. legal system is a direct heir of Roman law. The legal system that flourished and expanded from the second century BCE onwards in Rome and was codified in the centuries thereafter affected the development of European and ecclesiastical legal systems that, in turn, shaped the US Criminal Justice System.

You only have to visit Washington DC with its neoclassical architecture, said Bond, to see that how true this is. Half of the bas-reliefs that adorn the bronze doors of the Supreme Court depict ancient legal scenes and lawmakers. The Supreme Court website describes the overall scheme as representing “the evolution of justice according to the Western tradition.” The founding fathers read classical legal texts and thought with their systems of classification. You can see a copy of the Institutes of Justinian, the emperor Justinian’s sixth-century CE attempt to codify Roman law, alongside other important legal texts in Thomas Jefferson’s library.

One of the most troubling aspects of Ms. Spears’s claims was her statement that she has been prevented from removing an IUD so that she could not become pregnant. Not only has Spears expressed a desire to have more children but, at 39, the clock is ticking. Spears compared her experience to that of an enslaved sex worker. The comparison is apt: while historically most enslaved women have been coerced and forced into bearing children that would add to their enslaver’s workforce, the situation was different for sex workers whose ability to earn would be adversely affected. As an entertainer known for her slim build and energetic dance routines it seems that her “guardians” were concerned about her image. The implicit logic here seems to be that Spears’s career and, thus, earning potential would have suffered were she to become pregnant.

There is, however, another layer to this particular attempt to control Spears’s body and that is the history of ableism and eugenics in the American legal system. As activist Judy Heumann tweeted this week, conservatorship is “an abusive system that has been used against disabled people and older people for decades.” Those with mental health issues are especially vulnerable. In 1927 the Supreme Court upheld eugenic sterilization: in the decision Justice Oliver Wendell Holmes famously wrote that “three generations of imbeciles are enough.” As Adam Cohen observed in his book Imbeciles: The Supreme Court, American Eugenics, and the Sterilization of Carrie Buck over 70,000 people were forcibly sterilized in the U.S. as a result and—shockingly—the 1927 Buck v. Bell case has not been overturned despite opportunities to do so. As recently as 2001 a case heard at the U.S. Court of Appeals upheld a sterilization case by citing Buck v. Bell.

Britney’s experience is part of a lengthy history in which able-bodied people use medical diagnosis and mental health in order to control the reproductive rights of others. The situation is especially tragic when you consider that Britney’s conservatorship began as the result of a “meltdown” that took place in the context of an embittered custody dispute. Her desire to be a mother is denied and exploited at every turn.

Even in ancient Rome—a world in which women and children were considered legally and intellectually inferior—lawmakers were aware of the ways in which the system could be abused. They introduced measures, albeit ineffective ones, to prevent caretakers from taking permanent control of the wealth of their wards and allowing guardians to be sued for maladministration. They were expected to take an inventory of the ward’s assets, invest their money promptly, collect any debts owed to them, and ensure that they were well educated. If they didn’t do these things, they might be liable to pay interest. The responsibilities and burdens of guardianship were so high that many tried to avoid it citing infirmity or disability as a reason they could not serve.

It is, therefore, an indictment of our own system that someone as visible and demonstrably capable of supporting themselves as Britney Spears could be treated in this way. It makes you wonder how many others are stripped of their rights and civil liberties. As writer and activist Eric Michael Garcia put it “if the state can do this to one of the most influential pop stars in my lifetime, think what it can do to others.”