There were few towns in Medieval England and those that existed were very small by our standards. Most people in Medieval England were village peasants but religious centres did attract people and many developed into towns or cities.
Outside of London, the largest towns in England were the cathedral cities of Lincoln, Canterbury, Chichester, York, Bath, Hereford etc. That these cities were big can be explained simply because they were cathedral cities. These cities attracted all manner of people but especially traders and pilgrims. After the death of Thomas Becket in 1170, Canterbury Cathedral became a very special place of pilgrimage visited by thousands of people each year.
The Domesday Book of 1087 only included six towns in its enquiry. By the time of Medieval England, we do not have accurate figures for these towns and cities as no count was ever made of population and the figure would have changed throughout the year in all large towns and cities.
The big market fairs would have seen an increase in population and it may well have fallen after one had finished. Tax registers - such as the one that helped to spark off the Peasants Revolt of 1381 - were inaccurate as those who could get away with not registering did! If you were not on a tax list, you did not have to pay tax.
Medieval towns tended to grow around areas where people could easily meet, such as crossroads or rivers. Towns needed more water than villages, so a nearby water supply was vital. Rivers would provide the water used for washing and drinking and they were used for the disposal of sewage (if it had not been simply thrown into the streets).
Village people came to towns to trade therefore those who were in charge of a town had to do what was needed to ensure that their town was safe. Many towns had large fences built around them and the gates of these fences were locked at night to keep out undesirables. Cities such as York and Canterbury had city walls that served the same purpose - but a town would not have had enough wealth to build such an expensive protection.
A successful town attracted many merchants to it. Many towns were owned by a lord and it was in his interest to ensure that his town was popular with merchants as they paid tax. The more merchants in a town, the more tax a lord could collect. Taxes were collected by a sheriff. As many people could not read or write, the system was open to abuse and corruption. This is why many people in towns wanted to get a charter.
A charter gave people in a town certain rights that were clearly stated in the charter that town had. Many charters gave towns the right to collect their own taxes thus removing corrupt sheriffs from doing so. It was also common for a town to ask for its own law court so that legal problems could be settled quickly.
Towns were dirty places to live in. There was no sewage system as we would know it today. Many people threw toilet waste into the street along with other rubbish. Rats were very common in towns and cities and lead to the Black Death of 1348 to 1349. Towns might use pigs to eat what rubbish there was. Water was far from clean as a local river would have been polluted with toilet waste thrown into it from villages both upstream and downstream. Therefore, as people would have used this as a source of water (they had no other choice) and because people knew little about health and hygiene, disease was common. Life expectancy could be short. Life for a poor person in a town or city was described as "nasty, brutal and short".
As homes were made of wood, fire was another danger in a town or city. Walking in a town at night could also be dangerous. Though towns had a curfew (a time when everyone had to be in their homes) no town had a police force to deal with those who broke the law. No town had street lights - the only choice was candles but in a wooden city or town, these ‘street lights’ could prove disastrous.
Building in a Medieval town was expensive as land cost a great deal. That is why many Medieval houses that exist today appear odd in that they have a small ground floor, a larger second floor and an even larger top floor as builders built up and out. This kept the cost down.
A two-floored town house with the top floor over-lapping the ground floor
Shops attracted people to a town. The shops also doubled as a home for the craftsman that worked in it. A sign outside of the shop showed people what that person did for a living. Signs had to be used as so few people could read or write.