Gibraltar was "under a cloud of sorrow" on Friday a day after the death of Queen Elizabeth II at the age of 96, with the British enclave at the southern tip of Spain cancelling its national day, the chief minister said.
"The death of Queen Elizabeth II has been a dreadful blow for all British people and for the people of all her realms and commonwealth," Gibraltar's leader Fabian Picardo said in a statement.
"The whole of Gibraltar is under a cloud of sorrow today," he said, announcing the cancellation of the territory's September 10 national day which would have been its first post-pandemic celebration.
Known as The Rock, Gibraltar covers just 6.8-square kilometres (2.6-square miles) dominated by a massive limestone block whose white cliffs soar more than 400 metres (1,300 feet) above sea level.
"The (British) Prime Minister (Liz Truss) said her majesty had been 'the rock on which modern Britain was built'. I agree.. but I go one further," the chief minister said.
"Gibraltar was HER rock. And she was ours."
The queen visited Gibraltar only once, in May 1954, almost a year after she was crowned, with Picardo saying the enclave "cherished her visit... that left an indelible mark" and cemented its "loyalty to the crown".
While Spain ceded Gibraltar to Britain in perpetuity in 1713 following a military struggle, Madrid has long wanted it back in a thorny dispute that has created longstanding tensions.
But the 34,000 population has no interest in being anything but British.
Earlier, cannon fire rang out across Gibraltar as it joined the ceremonial "death gun salute" held across all four corners of the United Kingdom in memory of the late monarch, who died on Thursday at her Balmoral estate in Scotland.
Ninety-six shots were fired -- one for every year of her life -- from two sites in London, Edinburgh Castle in Scotland, Hillsborough Castle in Northern Ireland and Cardiff Castle in Wales, as well as the Channel Islands and Gibraltar.
On Saturday, when the late queen's son and successor is formally proclaimed the new sovereign, the Royal Gibraltar Regiment will at 1100 GMT fire a 21-gun salute "in honour of the proclamation in London of the new king, Charles III", Picardo said.