Upper lights of the stained glass window in the south wall of the choirboys' vestry, depicting the Siege of Derry in 1689. Unfortunately, the lower lights were hidden behind a wardrobe when this photograph was taken. The window was created by Powell & Sons and unveiled on 31 July 1913. (See Irish Times 1 August 1913, p. 6, and J. Godfrey F. Day and Henry E. Patton: "The Cathedrals of the Church of Ireland", p. 36–37.)