Anchoring the west end of the North Terrace is Winchester Tower. Others call this Wykeham Tower. These names recognize William of Wykeham, the former Bishop of Winchester and Chancellor of England. He was the primary administrator for the construction of the Upper Ward commissioned by King Edward III starting in 1357. The tower is at the beginning of the North Terrace, a promenade extending about half of the castle’s northern wall. This walkway was ordered by Queen Elizabeth I, the sister of Edward VI. She reigned from 1558 through 1603. When the Bubonic Plague began to ravish London, Queen Elizabeth I took refuge at Windsor Castle beginning in 1563. The North Terrace accommodated her desire for daily exercise.