THE DOWRY IN ANCIENT
A dowry, or dos as the Romans called it, was a part of most marriages. The Roman version of this very common institution probably began out of a desire to get the bride’s family to contribute a share of the costs involved in setting up a new household. Roman writers were quick to recognize that while they need not apply in every case there were other possible benefits. The dowry gave the bride’s family a reason to stay involved. In the early Republic the daughter often passed into the control of the groom’s family and the children certainly belonged to the husband and not the wife. Without a substantial investment in the dowry it would be tempting for the family of the bride to have little more to do with her, and a valuable dowry that could be withdrawn at will helped offset the power the law gave to the paterfamilias.
The father was more or less required, either by custom or law, to provide every daughter with a dowry appropriate to his means. If he were unable to do so a relative or a family friend might offer to provide one. If the woman were independent she could contribute her own property. The dowry was handed over to the husband or his paterfamilias as the bride’s contribution to the establishment of a new household. The husband was free to do what he wished with the dowry, but under the Julian law he was not allowed to sell any part of it without his wife’s permission.  In practice, this rule applied most often to immovables such as land and buildings, but whatever the contents of the dowry, he was under the absolute obligation of being able to return it or its equivalent value when required to do so, and the wise man kept it in a separate account. Otherwise, the dowry became part of the new family’s holdings and as such was administered like any other property by the paterfamilias.
Under Classical Roman law either the husband or the wife could demand and get a divorce without offering any reason beyond a simple desire to end the marriage. The record is silent on the need for paternal permission for those still in patria potestas, but certainly for childless couples divorce was otherwise quite simple, requiring little more than notification in the presence of witnesses that the marriage was over and that husband and wife now lived in separate premises. Given the ease and speed with which a divorce could be achieved, it is easy to imagine one spouse divorcing the other in the heat of an argument and then coming to regret it a few hours later; in that case the law regarded intent as the key, and pretended no divorce had ever taken place.  What happened to divorced wives? Those who could simply took their dowries and went home. Women with money and those without but still possessed of looks or charm had no trouble finding new husbands, for in the absence of adultery there was no stigma attached to the divorcee. There must have been divorced women long past the flush of youth with little wealth, and no family, but we have no way of knowing how many or what happened to them.
If the husband initiated the divorce he had to return the full dowry. Knowing this, the givers of advice, and every society has such people, urged husbands to keep the full dowry in a separate account so they would be able to fulfill this obligation when the time came, for the courts were adamant on the subject. Particularly large dowries were a major impediment to divorce as a high financial penalty had to be paid by the one who initiated it. The bigger the dowry the more power the wife had in the relationship as long as she remained chaste. If the wife (or in some cases her father) initiated the divorce, the husband was allowed to keep one-sixth for each child up to three plus, if applicable, another sixth for her adultery. 
Under the Augustan Marriage Laws a husband was required to divorce an adulterous wife or face charges of pimping. A woman who been convicted of adultery lost half of her dowry along with a third of any other property she possessed and was then exiled to an island.  Later in the Empire it was possible a woman could lose her entire dowry in the event of adultery or if she tried to get a divorce without presenting a valid reason.
 Gaius, Institutes, II.62
 Digest of Justinian, 24.2.3
 Rules of Ulpian, 6.9
 Ibid, 2.26.14