[3] The original hospital on the site was constructed by Aelred the Palmer, a Norman living in Dublin, after returning from a pilgrimage to the Holy Land.

[citation needed] In 1316 Edward Bruce marched towards Dublin at the head of his army, with the intention of besieging the city.

The Dublin citizens, to prevent any danger from his approach and by common consent, set fire to Thomas Street.

However, the flames laid hold of St. John's church and burned it to the ground, together with all the nearby suburbs.

[citation needed] About the commencement of the 18th century, an Augustinian Prior rented for their use as a chapel a stable on the western side of St. John's Tower, a surviving fragment of the hospital.

[5][9] There is a peal of ten bells hung in the tower, weighing 22 long hundredweight, 3 quarters and 2 pounds,[10] and in the key of D-flat.

The tower was not originally intended to hold bells, and therefore access is via an open iron staircase which was added later,[11] and which looks out into the nave of the church.