This book by Roy Adkins and Lesley Adkins describes in detail a 1770s siege by France and Spain against Gibraltar. A message from it is that British resources used to defend Gibraltar weakened their efforts in America. Thus Gibraltar helped America won the Revolutionary War. And of course that war is a follow-up to the French and Indian war.
https://www.warhistoryonline.com/history/great-siege-of-gibraltar-failed.html . In September of 1782, the great Spanish and French assault began. This massive organized assault was intended to be the final push to finally take Gibraltar. More and more infantry, ships and marines had been dedicated to the siege and by this time the original besieging force of 13,000 had grown to be over 60,000 men on land and sea.
The besiegers had built ten barge-type ships to bombard Gibraltar from the bay along with their many other ships. This was intended to weaken the garrison enough for the land forces to successfully invade. Tens of thousands of Spanish civilian spectators gathered on the hills around the bay to witness the attack. . The situation was moving in the British favor and with the end of the American War, they could provide more support to Gibraltar. The Spanish had taken some possessions in the West Indies and they were allowed to keep these, in return for Britain keeping Gibraltar.
The siege was one of the longest in British history, and it was fortunate that they endured as Gibraltar would play a major role in several wars.