All the troops of Philip were either on the frontier of Portugal or occupying the disaffected cities of the north.

At Madrid there were but a few troops of horse; in a week then, and possibly without shedding a drop of blood, Charles might have been proclaimed king in the capital of Spain.

The plan was, of course, not without danger.

Marshal Tesse, with an overwhelming force, would threaten the left of the advancing army, and the garrisons of the northern cities, if united, could march with equal superiority of force upon its right; but Tesse would be followed by Lord Galway and the allied and Portuguese army, while Barcelona and the other strongholds of Catalonia would rise if their garrisons were withdrawn.
Even in the case of failure Peterborough could have retired safely through Valencia and have re-embarked on board the fleet, or could have marched to Gibraltar.

The scheme was at once daring and judicious, but the Archduke Charles was slow and timid, and was controlled by the advice of his even slower and more cautious German advisers, and neither argument nor entreaty on the part of Peterborough could suffice to move him.