A Foot: What’s so special about 12 inches?
In the early days (and especially in rural areas) when measurements had to be made there wasn’t often any calibrated and standard measuring device handy. Therefore people did what people do best and improvised with what they had available to them. In many cases people would pace out a distance by walking it and give the unit of measure in “feet”. It is said that King Henry I of England, whose rule began in 1100, decided to standardize this unit of measure with his foot as the new standard unit of length. Most likely, due to the fact that people were generally shorter back then and also had shorter feet, the foot measurement standard was based on a booted foot rather than a naked foot. Additionally, there are many historical accounts of the width of a man’s thumb being used as a standard for an inch.