Ius primae noctis or the “right of the first night,” sometimes known as droit de seigneur, is a legendary right which was supposedly held by feudal lords. According to the terms of this right, the lord of the manor had the right to the marriage bed on the first night of a serf or peasant's marriage. Although numerous stories about ius primae noctis can be found, and the concept has been used as a plot device in many films and novels, some historical evidence strongly suggests that this right never existed.

Feudal lords certainly did have a great deal of power over the serfs and peasants who lived on their land, and they had a number of far-reaching rights, ranging from priority at harvest time to the right to hunt and fish freely. In the feudal era, residents of a manor were also tightly controlled by the lord, and they were expected to do his bidding, even if the legality of a particular order was not specifically spelled out in the law.

Legends about ius primae noctis are probably rooted in the tradition that peasants, serfs, and other residents of a manor needed to ask permission from the lord to marry. The idea was that the lord could potentially lose workers through a marriage, so he had a vested interest in controlling when and whom people married. Additionally, newlyweds were often required to pay a marriage tax to the Church, a form of tithing, and in some parts of Europe, the father of the bride was expected to make a payment to the lord of the manor to compensate him for the inconvenience of the marriage.

The traditions of asking for permission and paying bridal taxes are clearly documented in materials from the feudal area, suggesting that they occurred and they were widely accepted. Many descriptions of feudal weddings also include discussions of ribald joking and humiliating rituals which often played on the power of the lord. These actual events appear to have been conflated over time into stories about ius primae noctis.

Feudal life was rather unpleasant for people in the lower ranks of society, and in strict point of fact, most lords of the manor could and did force women to engage in sexual activity, whether or not they were married. Given that the lord's power over his serfs and peasants was widely accepted, he would hardly have needed a justification in the form of ius primae noctis to sleep with peasant women.