[1] For many years a gate provided access from the sea into the northwest of the town through the defensive wall that ran along the shore of the bay.

[6] The northern approaches to the town were defended by a Moorish Castle on the slopes of The Rock, from which walls ran down to the shore of the Bay of Gibraltar.

[7] Around 1310 Ferdinand IV ordered the Giralda Tower to be built on the coast at the west end of the wall to protect the dockyard.

[3] The Moors built a line wall, running south from the tower along the bay's western shore, which the Spanish later improved.

[8] The Giralda Tower was converted into the North Bastion by the Italian engineer Giovan Giacomo Paleari Fratino in the 1560s.

These were launched through a large arch in the line wall just north of today's Grand Casemates Gates, leading to the Waterport.

[8] The Waterport Gate, providing access to the town through the Line Wall from the shore south of North Bastion, was opened by the British in 1727.

Profane swearing and cursing is extremely common...[15]In 1802 Prince Edward, Duke of Kent and Strathearn was appointed Governor of Gibraltar.

An 1881 travel book described the keys being received from the governor twice daily and marched under escort to the gates, which were opened in the morning and closed each evening by a senior officer.

[23] After the armistice that ended World War I the future United States Admiral Jerauld Wright was a lieutenant on a destroyer that showed the flag in the Mediterranean.

There were two fifers, one drummer, and one little fellow following with those gigantic keys... they swung past, boots pounding, heads in the air, fife and drum rolling..."[24] Vice-Admiral Kenneth Dewar was in Gibraltar in 1928.

After the closing of the gates, a drum-and-fife band awoke the echoes in the narrow streets, accompanying a strong military guard which escorted the keys of the fortress to the Governor's Palace..."[25] The practice was discontinued for a while, then revived as an annual Ceremony of the Keys by General Sir Charles Harington when he took office as governor in 1933.

[28] Today, a version of the ceremony is staged in Casemates Square at noon every Saturday by actors in uniforms similar to those worn by the defenders during the Great Siege.