Surnames - the last name usually passed down to each male in a family - didn't even exist until approximately 1000 years ago. Today's bustling society relies heavily on specific names to identify each and every person, but back then the world wasn't nearly as crowded. People rarely ventured any more than just a few miles from where they had been born. Everyone knew their neighbors, so first names were all they needed. Even royalty were addressed by just a single name.
During the Middle Ages, family sizes began to grow and villages became more crowded. Among throngs of people, it was difficult to distinguish neighbors and friends from each other using only single first names. So the names became more descriptive. There might be "John, son of Jacob" and his neighbor "John, the blacksmith." Secondary names such as these still weren't surnames as we know them, because they were not handed down through generations from father to son. For instance, if "John son of Jacob" had a son, he might be called "Benjamin the carpenter."
Actual surnames - names used throughout hereditary lineage - didn't come into use until about 1000 A.D. in Europe. Members of royal families began the practice in many countries, choosing names according to their ancestral seats. However, many of the upper class people didn't begin using surnames until the 14th century. In about 1500 A.D., most of the surnames in use began to be inherited and passed down through families, rather than changing from one person to the next. The surnames that eventually developed drew their original meanings from four general categories.
One common way to differentiate people was to describe them according to their geographic locations. Nobility often chose surnames based on where their ancestral estates were located (Neville, Paris). If someone migrated from one spot to another, sometimes they were identified according to their original location (Roman, French). If a person lived near a river, forest, church, or other topographic feature, those items might have been chosen as a surname (Brooks, Churchill). During the Middle Ages, compass directions were a common means of identification (Eastwood, Westman).
Last names created by a father's name were often used to create surnames, especially throughout Scandinavian countries. Such surnames were derived by adding a prefix meaning "son of" and "daughter of" the original. Prefixes came from the language of the country, such as "Fitz" from the Norman languages; "Mac" from Gaelic languages' and "O" from Irish. Examples of patronymic names include Johnson (son of John), MacDonald (son of Donald), O'Brian (son of Brian), and Fitzhugh (son of Hugh).
Approximately 10% of all surnames were derived from physical characteristics of the first person. These names are believed to have originated as nicknames in the Middle Ages based on their personality or appearance. For example, if Michael had black hair, he became Michael Black. Peter the strong became Peter Strong. Such nicknames were created based on things such as an unusual body shape or size, facial hair, distinctive facial features or skin coloring, and even personalities or emotional traits.
Many surnames were created based on the occupation of the first person to have that name. These were usually related to the specialty trades and crafts of the Middle Ages, and they are pretty self-explanatory. For example, a Miller worked grinding grain into flour; a Taylor made or repaired clothing; a Wainwright built wagons; a Farmer was a farmer; a Fisher was a fisherman; and a Bishop worked for the clergy.
Although these basic classifications explain how many of today's surnames came into being, the variety continues to increase and expand constantly such that original derivations are impossible to discern. Many of the surnames in use today are probably simply corruptions of the originals - variations that are now disguised beyond recognition as their original form. Also, spelling and pronunciation has changed and evolved throughout the centuries. Therefore, if you want to find out where did your name come from, it is important to slowly work your way back through each generation and each family designation in order to arrive at the correct original name. The surname you have now might be entirely different from that of your distant ancestors. Doing the research and digging through your family tree will not only be interesting and enlightening, it might also yield some surprises.