At the naval battle of Camperdown, in 1797, the top of the British flagship's mainmast was shot away by a Dutch cannonball, bringing down the Admiral's colours. Lowering the colours was a sign of surrender, so the Dutch thought they'd won and the British became dispirited until crewman Jack Crawford grabbed the flag, and ignoring the musket shots whistling about, climbed the mast and nailed the colours in place, bringing new heart to the British, who went on to win the battle.

Propoganda being no different then to what it is now, there were efforts to turn Crawford into a popular hero, but he refused, lived the rest of his life in poverty, and eventually died during a cholera outbreak in his home town of Sunderland.

There's a statue of him, nailing the colours to the mast, in Mowbray Park, Sunderland, as mentoned in the song. And Bryan Talbot, in his brilliant graphic novel Alice in Sunderland, includes the story in a Boy's Own pastiche style.

(And if you ever have the chance to see Bob Fox, with or without the band, don't miss it.)