The rectangular Postern Tower (aka Bootham Tower) was built in 1497 to protect St Mary's Abbey and to control access via the adjacent postern (gateway).

The small square window below the eaves in the wall facing Bootham Bar is believed to date from the 17th century, when the original flat (or shallow-sloping) roof was replaced by the current hipped roof. These alterations allowed a third floor to be inserted into what had been previously been a two-storey building. The inserted window is clearly visible in Images 2 & 3 below.

Image 1

Photo as per caption. Opens larger version.
The southwest elevation of the Postern Tower, with the statue of William Etty and the Exhibition Square fountains in the foreground.

Image 2

Photo as per caption. Opens larger version.
The southeast elevation of the Postern Tower, with the perimeter walls of St Mary's Abbey (including 'Tower E') partially visible beyond.

Image 3

Photo as per caption. Opens larger version.
The southeast elevation from a slightly different angle. The outer face of Queen Margaret's Arch is also partially visible (left).

Image 4

Photo as per caption. Opens larger version.
The northeast elevation of the Postern Tower (right) and the outer face of Queen Margaret's Arch (left).

A lithograph (fine art print) produced circa 1840-1843 shows the tower as having a doorway from Bootham, beside a projecting bay window. The bay window was replaced in the 19th century and the replacement had wooden shutters with massive ornate hinges. The timber components of the shutters have since been replaced, but the original hinges are still in situ and they are worth a quick glance if the shutters are closed.

The reason for the insertion of the postern tower and gateway into the walls around St Mary's Abbey is explained on the page for Queen Margaret's Arch.