Most medieval bynames were simple and straightforward: your father's name, your home village, your occupation, or perhaps some notable personal characteristic. Sometimes the same kinds of ideas were expressed in more elaborate ways, but the ideas remained very down-to-earth.
Bynames basically come in four flavors:
These four types of byname are found in almost every medieval European culture, though of course the relative frequency and grammatical construction vary considerably from one language to the next . We've chosen to illustrate this discussion with medieval English examples, but the general principles apply to most medieval European languages. The indented paragraphs delve a little more deeply into English naming practices, and don't apply generally. An appendix lists good sources for choosing bynames from other medieval languages.
A patronymic byname identifies you as your father's child. Patronymics are an old and common type of byname in most period European cultures. English and some other cultures also used metronymics, bynames referring to your mother; they did _not_ connote bastardy. Not all cultures used metronymics, though, and patronymics were always more common.
A locative byname identifies you by the place where you live, work, or were born, or by the land you own. There are two broad categories of locative: toponymic and topographical.
A toponymic byname refers to a named place, i.e., it incorporates a proper noun.
Topographical bynames refer to features of the local landscape, either natural or man-made. In a sense, your byname is your address: It tells people where you live or where you work.
In general, someone was named after a large place only after he left it: The name Simon Welsche 1279 wouldn't distinguish a man from every other Simon in Wales; but it was apparently a good identifier in Bedfordshire where Welshmen were rare. People were usually named after large places when they had moved a long distance. On the other hand, Richard Overthegate 1327 would hardly have been a useful identifier if Richard ventured more than a few miles away from the gate for which he was named.
Occupational and status bynames identify you by an occupation or rank. In this category we include both literal identifications, like John Smith for a man who was a smith, and figurative descriptions, like Agnes le Pope c.1230, who certainly was not the Pope! Something about her behavior led people to give her that byname, which could well have been sarcastic or even insulting.
An important category overlaps between locative and status bynames: ethnic bynames. These are bynames which identify you by your nationality, religion, or ethnic group. In many cases, they are based on much smaller regions than the nationalities we used in the modern world, right down to cities and towns. William le Bret 1230 was a Breton or Briton, while Hugh le Pycard 1276 was from Picardy in northwestern France.
Nicknames are a grab-bag of all bynames that don't fit into any of the first three classes, but some common types can be identified. In this class we include nicknames describing physical, mental, or moral characteristics of the bearer. Many were derogatory and others were ironic: although they appear to be complementary, they were not. For example, Henry Bigge 1177 might have been a small man. The most common nicknames were very simple and concrete: Hamo le Reed 1296 'the red', Roger le Wis 1203 'the wise'. Others were more abstract: Gilbert Wysdom 1243, Walter Boost 1327 'boast'. A common category was metonymic bynames, which identified your occupation by naming a tool you used or a product you produced or sold. Thomas Mayle 1296 could have been a maker of mail armor and Geoffrey wythe Hameres 1303 'with the hammers' was a maker or user of hammers rather than a man who owned some notable hammers.
Other English descriptive bynames refer to articles of clothing, e.g., Wytebelt 1307 'white belt', Wythemantel 1297 'with the mantle'; Scortmantil 1312 'short mantle'. In some cases, like Gilbert Hodde 1225 'hood', such bynames may be occupational rather than physically descriptive: Gilbert may have been a maker of hoods. Robert Rotenheryng 1297 'rotten herring' was probably a fish-seller!
Other conditions not falling into any of the foregoing categories can be described by nicknames: John le Wyfles 1327 presumably had no wife. Occasionally one finds nicknames apparently commemorating a particular event, like Falinthewol 1301 'fall in the well', though this particular name is found often enough to make us wonder whether it embodies some popular expression; perhaps it refers to a dreamer or a very clumsy person. Perhaps a better example is the rather cryptic Latethewaterga 1242 'let the water go', about which one could produce endless conjectures! In general, though, these complex, cryptic nicknames are rare. They didn't exist in every language.
In conclusion we can't resist mentioning Henry Lytilprud 1301 'little worth' and his wife Hawisia Crist a pes 'Christ have peace!'; her byname probably records a favorite expression of this apparently long-suffering woman.
The Difference Between Typical SCA
Bynames and Medieval Bynames
Sources for Medieval Bynames
 Some cultures used some types of byname very rarely or not at all. For example, Gaelic names very rarely include locative bynames. Gaels used patronymic bynames almost exclusively, but essentially never used metronymics.
 It is even possible that such examples are over-literal English translations of documentary quasi-French forms like de la Felde 1188 and del Feld 1190, though there is probably no way to be sure.
Layout, editting, and publishing by Arval Benicoeur.