The building was heavily rebuilt during the 18th and 19th centuries in the Georgian style with Victorian elements. It was Colonel William Hargrave (Governor of Gibraltar 1740-1749), who ordered the west part of the chapel be cut in half and rebuilt in order to accommodate the Supper Room. He used the material removed from the Convent to build storehouses in Casemates Square.14 The 1753 Montresor map, however, still shows the Church before it was truncated. From this point onwards, the entrance to the King’s Chapel was now directly through the Convent itself.
The convent gardens include trees planted by Royalty such as King Edward VII; the German Emperor Wilhelm II; Prince Hirohito, Crown Prince of Japan; and Her Majesty Queen Elizabeth II. During Boyd’s time, the gardens still had no enclosure walls and became what the Alameda Gardens would become much later – a place for social gatherings. A visitor in 1772 noted:
“The governor’s garden is open to the public, and is much resorted to on Sunday evenings.”
On the 15th September 1779, Elliot ordered the “pavements of the streets be ploughed up…. Steeples, towers, and all objects that might serve for marks be pulled down.”15 As a result the arch and the upper part of the upper part of the chapel was taken down in the general removal of all conspicuous artillery targets.
During the Great Siege, King’s Chapel was used as a store for ‘dry goods’ whilst religious services were sometimes held in the Cloister. The Governor’s suite of offices and the Supper Room was further reinforced to make them bombproof.16 The Convent suffered heavy damage during the siege but Elliot repaired the damage whenever possible. As a result, the building had to undergo extensive repairs in the years following the siege. The south transept and 61 feet of the heavily damaged nave were excluded when the repairs were carried out. Garrison orders records that the Chapel was reopened for Divine Service in 1788.
Drinkwater wrote that the new dining tables, made out of cedar wood, and other pieces of mahogany were salvaged from the wrecks of the floating batteries.17 The holes and burn marks of the panels on the doors are still evident to this day.
The King’s Chapel was also repaired and became the Garrison Chapel resplendent the colours of several British regiments. Beneath the colours can be found a number of sepulchres within the walls and floors of the Chapel dating back to the Spanish period. Amongst the most notable are the remains of the wife of the Spanish governor dated to 1648 and two British governors: General Charles O'Hara and Lieutenant-General Colin Campbell, who were laid to rest in 1802 and 1814, respectively.
When HRH the Duke of Kent arrived as Governor in 1802, the Convent was still in a state of disrepair and so he took up residence at what is now the Duke of Kent House instead. He proposed a very substantial reconstruction of the Convent but was recalled before the expenditure could be approved. His successor, Lt. General Sir Thomas Trigge proposed a more modest estimate of around £8,000 but even on this amount he expressed serious doubts as to its urgency. He did however propose a new gallery ‘to communicate with the rooms’ at a cost of £300.
A further modification was carried out by Governor Don in 1814 when concerned with worshippers entering the Chapel through the main entrance ordered a small house to the immediate left of the main entrance be pulled down and a new entrance into the north transept be built instead.18 Further repairs to the Convent proved particularly expensive and accounted for half the sum expended in public works in the colony of Gibraltar.19 For example, the present dining room was reconstructed in 1864 and cost over £4,000. The room contains an array of Coats of Arms, flags, mottoes and paintings dating back to 1704. Some of the panels are emblazoned with the arms of Moorish Caliphs, Spanish and British Monarchs dating as far back as 711.
In 1833 the Chapel was closed upon completion of the new Garrison Church (Holy Trinity Cathedral) which was met with vigorous protests in Gibraltar. The congregation were told that they would have to pay a pew rent sufficient to maintain a military chaplain at a cost of five shillings a day.20 They were apparently unwilling to do so, however, services resumed between 1843 and 1844 when the chapel was restored by the Royal Engineers at a cost of £340 3s 3¾d to serve as an auxiliary place of worship for Gibraltar's civilian population. So many military personnel were now using the Cathedral of the Holy Trinity that there was little room left for the civilians.21 The Assistant Military Secretary at the time summarised the situation in a letter of 8th March 1844:22
"When the Governor assumed the government, he found the Convent Chapel in a neglected, dark, unwholesome state and a sephulchral nuisance to the residence ... [T]he Bishop and Archdeacon stated to the Governor that the Protestant community at large experienced great inconvenience from the Cathedral being so filled by the military that insufficient space was left for the civilian congregation. The Governor therefore applied for and obtained permission to restore the Chapel as an auxiliary or Chapel of Ease to the Cathedral, and not, as heretofore, the sole place of worship for the Garrison."