Being fortunately independent of orders, Peterborough marched for Castile, as he and the council of war had previously determined.
Charles was not long in regretting that he had not followed Lord Peterborough's advice.

Instead of the triumphant procession from Saragossa to Madrid, which he had been promised, he was met with the most determined opposition.
Every town and village in the center and south of Spain rose against him; Salamanca and Toledo declared for Philip, and Andalusia raised eighteen thousand men.

The troops of Las Torres from Valencia, and those who had retreated under Tesse to Roussillon, had joined Berwick at Xadraque, and Philip had placed himself at the head of this formidable army.

Charles was obliged to send in the utmost haste to ask the Earl of Peterborough to extricate him from the position in which he had placed himself by neglecting his advice.
The earl instantly complied with the request, and marching with all speed overtook the king on the 4th of August at Pastrina, and thence on the following day escorted him in safety to the army of Portugal at Guadalaxara.
The total strength of the united allied army was eighteen thousand men--a force inferior, indeed, to that with which Berwick confronted them; and that portion brought by Lord Galway and the Portuguese General Das Minas was not to be relied upon, having fallen into a state of great indiscipline owing to the tedious delays, the frequent retreats, and the long inactivity to which it had been subjected by the incompetence of its leaders.

That this was so was evident by the fact that the day after the king's arrival the French made a partial attack, and many of the allied battalions at once fell into complete confusion.