The Prince of Wales has joined thousands of international services personnel at the start of a UK-led military exercise.
Joint Warrior involves 30 warships and submarines, 60 aircraft and more than 6,000 troops from 12 countries.
It is one of the biggest Nato exercises in Europe, with the Royal Navy, Army and Royal Air Force all involved.
Charles, who is Commodore-in-Chief of the Canadian Royal Navy's Fleet Atlantic, joined crews of two participating Canadian vessels at HM Naval Base Clyde today to mark the start of the exercise.
Known as the Duke of Rothesay while in Scotland, Charles met captains and crew of Canadian ships Montreal and Windsor at Faslane and was told about the 13-day Joint Warrior exercise.
Involving troops from the UK, US and other Nato members, it is designed to improve "inter-operability and warfighting capability at sea" and will take place off the west and east coasts of Scotland.
Defence Secretary Michael Fallon said: "This UK-led exercise is a powerful demonstration of Nato's collective determination to defend our allies against any threat.
"Training with other nations' forces on land, sea, and in the air, will significantly enhance our ability to conduct joint operations."
Commodore Toby Williamson, Commander Operational Training, said: "Exercise Joint Warrior is an opportunity to practice with and against our coalition partners, experiment and learn from them, and ultimately hone our tactics to the highest possible level.
"Sometimes, a single warship is able to fight alone and unafraid, but normally, the UK would provide security at sea as part of a task group, integrated across land, sea and air, alongside our coalition partners."