The object of the Royalist invasion was, by a powerful diversion, to compel the Argentine Government to withdraw their army from the Banda Oriental for the protection of the northern provinces, but meantime that government had armed and equipped a small naval force, which, under the command of an Irishman named Brown, had, on the 16th May, defeated and almost destroyed the Spanish squadron stationed at Monte Video, which city soon after surrendered to the Argentine army then besieging it under the command of Alvear.
Before the conclusion of these events, the General of the Army of the North had disappeared from the theatre of war. San Martin, after careful study of the question, had clearly discerned that the road by Upper Peru was not the true strategical line of the South American revolution. His idea was to carry the war to the West, to pass the Andes, to occupy Chile, to secure the dominion of the Pacific, and to attack Lower Peru on the flank, continuing military operations to the North merely as a subordinate detail of the main design.
This plan, the merits of which were not appreciated by his contemporaries until it was crowned with victory, is looked upon by posterity as not merely the most simple, but as the only possible plan which could give the desired result. It was then held to be folly, whilst in reality the folly lay in persevering in the attempt to reach Lima with insufficient means and by an impracticable route. Knowing that it would be looked upon as folly, San Martin kept his idea to himself, as his secret, as he himself styled it in confidential intercourse, waiting to disclose it for the day when he should hold in his hand the thunderbolt which was to shatter the power of Spain in America. Three months after taking command of the Army of the North, he wrote to his friend, Don Nicolas Rodriguez Peña:—
"Don't flatter yourself with thinking of what I can do here. I shall do nothing, and nothing here pleases me. Our country can do nothing more here than act on the defensive,
