A bastard (also called whoreson) in the law of England and Wales is a person whose parents were not married at the time of his or her birth. Unlike in many other systems of law, there was previously no possibility of post factum legitimisation of a bastard. This situation was changed in 1926.
The word bastard is from the Old French "bastard," which in turn was from medieval Latin "bastardus." According to some sources, "bastardus" may have come from the word "bastum," which means packsaddle, the connection possibly being the idea that a bastard might be the child of a passing traveller (who would have a packsaddle). In support of this is the Old French phrase "fils de bast" loosely meaning "child of the saddle," which had a similar meaning.