The 21-gun salute originated as a British naval custom.

The reason for any cannon shot being offered as a salute

was that firing a round meant that the gun

was disarmed for the considerable amount of time it took to reload.

This period of disarmament, was the real sign of respect.

A person of great stature was given a multi-shot salute,

but always an odd number because sailors thought even numbers brought bad luck.

Heads of state got the maximum, 21 guns,

because that's how many cannon were mounted on the side of a major ship of the line.