Tower of London

During the civil war called the Wars of the Roses in the years 1377 - 1485, when England was divided into two houses of Lancaster and York and their supporters, the character of the Tower changed.

An excerpt from the article 21 facts about Tower of London

It became a prison where King Henry VI, who threatened the new ruler Edward IV, was imprisoned and later probably murdered. Later, Edward's sons found themselves in this prison after their uncle Richard III took the throne. The Tower of London became a prison for the high-born inhabitants of England. This tradition was continued by subsequent rulers.