Legitimacy, in traditional Western common law, is the status of a child born to parents who are legally married to each other, and of a child conceived before the parents obtain a legal divorce. Conversely, illegitimacy (or bastardy) has been the status of a child born outside marriage.
Depending on the local legislation, legitimacy can affect a child's rights of inheritance to the putative father's estate and the child's right to bear the father's surname or title. Illegitimacy has also had consequences for the mother's and child's right to support from the putative father.
England's Statute of Merton (1235) stated, regarding illegitimacy: "He is a bastard that is born before the marriage of his parents." This definition also applied to situations when a child's parents could not marry, as when one or both were already married or when the relationship was incestuous.
The Poor Law of 1576 formed the basis of English bastardy law. Its purpose was to punish a bastard child's mother and putative father, and to relieve the parish from the cost of supporting mother and child. "By an act of 1576 (18 Elizabeth C. 3), it was ordered that bastards should be supported by their putative fathers, though bastardy orders in the quarter sessions date from before this date. If the genitor could be found, then he was put under very great pressure to accept responsibility and to maintain the child."
Under English law, a bastard was unable to be an heir to real property and could not be legitimized by the subsequent marriage of father to his mother. There was one exception: when his father subsequently married his mother, and an older illegitimate son (a "bastard eignè") took possession of his father's lands after his death, he would pass the land on to his own heirs on his death, as if his possession of the land had been retroactively converted into true ownership. A younger non-bastard brother (a "mulier puisnè") would have no claim to the land.