The surname of AHL was a German nickname for a slippery individual, or a metonymic occupational name for an eel fisher, originally rendered in the Old German AL. The first hereditary surnames on German soil are found in the second half of the 12th century, slightly later than in England and France. However, it was not until the 16th century that they became stabilized. The practice of adopting hereditary surnames began in the southern areas of Germany, and gradually spread northwards during the Middle Ages. It was also a Swedish ornamental name meaning 'the dweller where the alder trees grew'. Many of the modern family names throughout Europe reflect the profession or occupation of their forbears in the Middle Ages and derive from the position held by their ancestors in the village, noble household or religious community in which they lived and worked. The addition of their profession to their birth name made it easier to identify individual tradesmen and craftsmen. As generations passed and families moved around, so the original identifying names developed into the corrupted but simpler versions that we recognise today. Over the centuries, most people in Europe have accepted their surname as a fact of life, as irrevocable as an act of God. However much the individual may have liked or disliked the surname, they were stuck with it, and people rarely changed them by personal choice. A more common form of variation was in fact involuntary, when an official change was made, in other words, a clerical error. Among the humbler classes of European society, and especially among illiterate people, individuals were willing to accept the mistakes of officials, clerks and priests as officially bestowing a new version of their surname, just as they had meekly accepted the surname they had been born with. In North America, the linguistic problems confronting immigration officials at Ellis Island in the 19th century were legendary as a prolific source of Anglicization.