Construction of the walls
It is difficult to assess how the walls and moats were actually built in c.1100-1125 since there is no evidence, documentary or otherwise about the massive programme of works which must have dominated events in Dublin at this time. Defence was seen as a matter for each individual, as the Hiberno-Norse community at Dublin was relatively isolated and in what was essentially a hostile environment. Several details about the defences can be gleaned, however, from the surviving sections of the wall. The wall was constructed of limestone blocks probably quarried as bedrock is close to the surface in Dublin. It had a rubble core and was mortared with various lime mortars of different types.
There is more information about the methodology employed during the Anglo-Norman refortification programme due mainly to the documentary sources. We know, for instance, that the defence of the city was compelled to each citizen. This message was very much to the fore in the instruction received from King John with regard to the building of Dublin Castle in 1204. He specifically ‘commanded that the citizens fortify their city and that the justiciar compel them if they do not do so’. A second pronouncement in the same year urged ‘every one for his part’. Bearing this in mind it is most likely that the defensive programme was a community effort, the bulk of the labour provided by all the available men in the city. There was certainly a ‘right of way’ both along the wall-walk and the base wall of the wall which suggests a communal responsibility.
The refurbishment programme required new stone, and at least 2 quarries have been located through excavation, one at Essex Street West and one at South Great George’s Street. It’s believed that that the limestone from Essex Street West suggests was cut out in steps and that blocks were roughly hewn at the site before being transported away, presumably utilizing the Liffey and the Poddle for that purpose. The lime mortar was likely made along the route of the wall, as in one location. At Patrick’s Street a mortar kiln was found close to the wall presumably where it produced lime from limestone to make the mortar mix. The discovery of the kiln is also important as it predates the rechanneling of the Poddle into the city moat, suggesting that the wall was rebuilt first and the digging of the ditch followed
There is more information about the methodology employed during the Anglo-Norman refortification programme due mainly to the documentary sources. We know, for instance, that the defence of the city was compelled to each citizen. This message was very much to the fore in the instruction received from King John with regard to the building of Dublin Castle in 1204. He specifically ‘commanded that the citizens fortify their city and that the justiciar compel them if they do not do so’. A second pronouncement in the same year urged ‘every one for his part’. Bearing this in mind it is most likely that the defensive programme was a community effort, the bulk of the labour provided by all the available men in the city. There was certainly a ‘right of way’ both along the wall-walk and the base wall of the wall which suggests a communal responsibility.
The refurbishment programme required new stone, and at least 2 quarries have been located through excavation, one at Essex Street West and one at South Great George’s Street. It’s believed that that the limestone from Essex Street West suggests was cut out in steps and that blocks were roughly hewn at the site before being transported away, presumably utilizing the Liffey and the Poddle for that purpose. The lime mortar was likely made along the route of the wall, as in one location. At Patrick’s Street a mortar kiln was found close to the wall presumably where it produced lime from limestone to make the mortar mix. The discovery of the kiln is also important as it predates the rechanneling of the Poddle into the city moat, suggesting that the wall was rebuilt first and the digging of the ditch followed
civilian life on the walls
Citizens were in the habit of erecting houses on the city walls; this right was questioned a lot. John de Grauntsete and his spouse Alice were tenants in 1317 of stone houses on the walls which were erected without permission of Geoffroi de Mourton. Any building which caused an obstruction to the defence of the wall was destroyed, but through the requests of the tenants, was allowed to be rebuilt. However a restriction was applied to the citizens to allow an ample amount of space to the wall on a breadth of three and a half feet. This helps give an idea of the width of the city walls. In 1452 there are reports of more houses on the walls as it was ordered that those who wished to erect should show their title or else the Mayor and Commonalty might enter into possession.