By 1805, the north transept was in ruins and the south transept was in a poor condition; urgent work was carried out to the nave roof, held up by scaffolding.

In 1846, the post of Dean of Saint Patrick's was united with that of Dean of Christ Church, a situation which lasted in law until 1872.

An attempt at major restoration began under the direction of Dean Pakenham (Dean, 1843–1864), limited by poor economic circumstances.
The Lady Chapel was restored, the floor (then raised several metres) reduced to its original level and other urgent matters were at least partly addressed.

In the mid-19th century, a Celtic cross was found buried near the cathedral.
This has been preserved and it is thought it may have marked the site of the former holy well.

The major reconstruction, paid for by Benjamin Guinness, in 1860–65, and inspired by the fear that the cathedral was in imminent danger of collapse, means that much of the current building and decoration dates from the Victorian era; medieval chantries were removed among other actions, and few records of the work survive today.

Though the rebuilding ensured the survival of the cathedral, the failure to preserve records of the scale of the rebuild means that little is known as to how much of the current building is genuinely mediæval and how much is Victorian pastiche.
Sir Benjamin's statue by JH Foley is outside the south door.
His son Arthur (also a brewer) came in for humorous but gentle criticism when he donated a stained glass window of 'Rebecca at the well'; its motto read: 'I was thirsty and ye gave me drink'.
In 1901 his son Edward created the adjacent "St Patrick's Park" from an area of decrepit housing, and donated a new set of bells to the cathedral.

The other great change for the cathedral occurred in 1871 when, following disestablishment of the Church of Ireland, the newly independent church at its general synod finally resolved the "two cathedral" issue, making Christ Church the sole and undisputed cathedral of the Dublin diocese and St Patrick's the national cathedral.
By 1805, the north transept was in ruins and the south transept was in a poor condition; urgent work was carried out to the nave roof, held up by scaffolding.
In 1846, the post of Dean of Saint Patrick's was united with that of Dean of Christ Church, a situation which lasted in law until 1872.
An attempt at major restoration began under the direction of Dean Pakenham (Dean, 1843–1864), limited by poor economic circumstances. The Lady Chapel was restored, the floor (then raised several metres) reduced to its original level and other urgent matters were at least partly addressed.
In the mid-19th century, a Celtic cross was found buried near the cathedral. This has been preserved and it is thought it may have marked the site of the former holy well.
The major reconstruction, paid for by Benjamin Guinness, in 1860–65, and inspired by the fear that the cathedral was in imminent danger of collapse, means that much of the current building and decoration dates from the Victorian era; medieval chantries were removed among other actions, and few records of the work survive today.
Though the rebuilding ensured the survival of the cathedral, the failure to preserve records of the scale of the rebuild means that little is known as to how much of the current building is genuinely mediæval and how much is Victorian pastiche. Sir Benjamin's statue by JH Foley is outside the south door. His son Arthur (also a brewer) came in for humorous but gentle criticism when he donated a stained glass window of 'Rebecca at the well'; its motto read: 'I was thirsty and ye gave me drink'. In 1901 his son Edward created the adjacent "St Patrick's Park" from an area of decrepit housing, and donated a new set of bells to the cathedral.
The other great change for the cathedral occurred in 1871 when, following disestablishment of the Church of Ireland, the newly independent church at its general synod finally resolved the "two cathedral" issue, making Christ Church the sole and undisputed cathedral of the Dublin diocese and St Patrick's the national cathedral.
St Patrick's Cathedral, Dublin