During the Middle Ages surnames were first used in order to distinguish between numbers of people bearing the same christian name. As taxation, under William The Conqueror, who invaded England in 1066, became the law, documentation became essential, and names were chosen from a man's trade, his father's name, some personal physical characteristic, or from his place of residence. Surnames derived from placenames are divided into two broad categories; topographic names and habitation names. Topographic names are derived from general descriptive references to someone who lived near a physical feature such as an oak tree, a hill, a stream or a church. Habitation names are derived from pre-existing names denoting towns, villages and farmsteads. Other classes of local names include those derived from the names of rivers, individual houses with signs on them, regions and whole countries. This German name of ALSPAUGH was of the locational group of surnames meaning 'the dweller at the mountain stone' from residence nearby. 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. Surnames as we know them today were first assumed in Europe from the 11th to the 15th Century. The employment in the use of a second name was a custom that was first introduced from the Normans. They themselves had not long before adopted them. It became, in course of time, a mark of gentler blood, and it was deemed a disgrace for gentlemen to have but one single name, as the meaner sort had. At first the coat of arms was a practical matter which served a function on the battlefield and in tournaments. With his helmet covering his face, and armour encasing the knight from head to foot, the only means of identification for his followers, was the insignia painted on his shield and embroidered on his surcoat, the flowing and draped garment worn over the armour.