The earliest reference to ‘colours’ as a means of identification can be traced back to the English navy, who adopted the term in 1706 to describe their flags of identity. Since then, we have regularly used expressions containing the term, such as to Nail One’s Colours to the Mast. We will often hear this said of a person who is resolute in his or her principles or view of events and prepared to make them public knowledge. We might even take it as a declaration of allegiance. Since 1706, battleships around the world have flown their national ensign proudly from both the mainmast and at other points on the vessel. In times of battle, a flag might be lowered as a sign of surrender, as any ship taking a pounding could lower the main flag and capitulate. But it might not be a captain or senior officer taking that decision. Any frightened sailor, amid the chaos of battle, could loosen the rope and take his chances as a prisoner of the enemy. Let’s face it: an able seaman would simply be put back to work aboard the conquering ship – a considerably better option to a watery end.
To prevent this, dedicated and brave sea captains might order the flag rope to be literally ‘nailed’ into the mast, preventing any sign of surrender being made during battle. Since the early 18th century, the term has been used to describe a determined or principled person. Sir Robert Peel used the phrase in the Croker Papers (1844) when he ridiculed a political opponent: ‘I have never heard him (Ashburton) make a speech during the course of which he did not nail, unnail, renail and unnail his colours again.’ Arnold Bennett when writing The Matador of the Five Towns (1912) included the line: ‘She could not conceive in what ignominy the dreadful affairs would end, but she was the kind of woman that nails her colours to the mast.’
Extract from Money for Old Rope Parts 1 & 2