France agreed not only to furnish an army for the invasion of England but never to make peace until Britain had handed back Gibraltar.

The allies planned to seize and hold the Isle of Wight.

England has often been threatened and yet has been so long free from the tramp of hostile armies that we are tempted to dismiss lightly such dangers.

But in the summer of 1779 the danger was real.

Of warships carrying fifty guns or more France and Spain together had one hundred and twenty-one, while Britain had seventy.