Construction began during William I's reign, which lasted from 1066 to 1087. The building's first stage was completed in 1078. It was repaired, strengthened, maintained, and enlarged during subsequent reigns and now consists of 20 towers on an 18-acre site next to the Thames River. It was originally built to intimidate the English populace and to provide a place of safety for the king during times of danger. It has been periodically used as a government jail or prison. Many prisoners were political; others were not. Numerous clergy and royal family members accused of various real or invented crimes were incarcerated in the Tower. Some were executed. The majority of prisoners during the Tower's early years lived in large, luxurious rooms. Gradually the captives' situations became less comfortable. The last beheading at the Tower took place in 1747. As time went on, other prisons in and around London housed prisoners and the Tower's use declined. However, it still housed a few prisoners in the 20th century. It no longer holds anyone. Notes and 14 references