The Middle Ages (also called the medieval period) was a period of time that lasted in regards to a thousand years from your 5th for the 15th centuries. It is often subdivided into three periods with all the first being the Early Middle Ages, the other defined as the High Middle Ages, and also the third and final known as the Late Middle Ages. Arthritis is often associated with the elderly, but it can also affect children. In the UK, about 15,000 children and young people are affected by arthritis.