The Argentine Government had secret agents in Cadiz, who kept them well informed of all that went on. These men reported great discontent among the troops in cantonments on the island of Leon, and that there was a conspiracy on foot to proclaim the Constitution of the year XII., in which most of the superior officers were implicated.

General O’Donnell, aided by General Sarsfield, affected to join the conspiracy in order to discover the plan of it, but when it was on the eve of breaking out, issued a proclamation to the troops, calling upon them to adhere to their allegiance, and promising them, among other rewards for their loyalty, that they should not be sent to America. The leaders of the conspiracy were without difficulty arrested, but the projected expedition was thus prevented from sailing. In July, 1819, yellow fever broke out in the army; but in spite of all this, Government was still resolved to send off the expedition. The Count of Calderon was put in command, and the Minister of Marine was instructed, in September, to embark the troops at once.

In July of this same year 1819, General Rondeau was, by the influence of the Lautaro Lodge, appointed Supreme Director of the United Provinces in place of Pueyrredon. This was merely a change of names, the reins of power remained as before in the hands of the oligarchy which had ruled for so many years. One of the first acts of the new Government was to send for San Martin to come to Buenos Ayres, to consult on the measures to be adopted in view of the threatened expedition from Spain. San Martin was himself full of apprehension, but without consulting his own Government, he proposed to O’Higgins that the Chilian squadron, under Cochrane, and in the pay of the Argentine Government, should sail to meet the expedition on the Atlantic and destroy it in the open sea, offering to pay at once 50,000 dollars towards the expenses.

This scheme would, he thought, have great attraction for the enterprising spirit of the Admiral, but Cochrane, bent upon destroying the Spanish fleet at Callao, would not listen to it until the business in hand was accomplished, when there would, he said, be ample time yet to meet the new fleet on the Atlantic and blow them to pieces with his Congreve rockets.

In answer to a second letter from Rondeau in August, San Martin offered to march with 4,000 men, of whom 3,000 would be cavalry, to drive the Spaniards into the river, as he had done before at San Lorenzo; “with sixteen squadrons and thirty light field pieces we can be sure of victory.”

In October news was received in Buenos Ayres that O’Donnell had rebelled against the Spanish Government, and had marched with the army of Cadiz upon Madrid. This news was false, but it had the effect of causing Rondeau to countermand the orders for the concentration of the army.

Meantime the truce between the central Government and the Gaucho chieftains of the interior had come to an end. Ramirez from Entre Rios, and Artigas from the Banda Oriental, had joined hands with Lopez of Santa Fé, and war had again broken out on the northern frontier of Buenos Ayres. For the third time Government looked to San Martin for help, and ordered him to Buenos Ayres, with the division quartered at Mendoza. Just at the same time he received advices from Chile that all was ready for the proposed expedition to Peru. San Martin hesitated, but wrote to Government that he was about to march to Buenos Ayres with 2,000 cavalry and eight guns, but should leave his infantry in Mendoza. One battalion of infantry was quartered in San Juan, the grenadiers were in San Luis, and his total force of regular troops in Cuyo was now raised by recruiting to 2,200 men, besides which he had called out the militia of San Luis to the number of 2,000 men.

The idea of Government was to concentrate the whole army in the Province of Buenos Ayres to the number of 8,000 or 10,000 men, ready to act either against the Spaniards or against the Gaucho hordes, but as the latter numbered only 1,500, it was a most cowardly measure to abandon the northern frontier, menaced by the Royalists of Upper Peru, and to break the terms of the alliance with Chile, and could only have ended in the isolation of Buenos Ayres from the rest of the provinces. The civil war was a spontaneous effervescence of the people, and could not be cured by the sabre. It arose not only from the semi-barbarous instincts of the masses, but also from the discontent of the more educated classes with a political system which was not in accordance with the principles of the Revolution, and this discontent permeated the ranks of the army itself.

Rondeau, in pursuance of his plan, took the field with the Army of Buenos Ayres, and marched to the northern frontier of the Province, against the Gaucho hordes, seeking a junction with the Army of the North, coming from Cordoba. His army alone was superior in number to the enemy. Why, then, did he send for another army from Cuyo?

The real object of this concentration was that Gomez, the Argentine envoy in Paris, had entered into an arrangement with the French Government to crown the Duke of Luca, a Prince of the House of Bourbon, King of the United Provinces; France engaging on her part to divert the projected expedition from the River Plate, and to secure the acquiescence of Portugal and the evacuation of the Banda Oriental by marrying the future king to a Brazilian Princess. Congress, setting at naught the Republican constitution so lately sworn, and without any attempt to consult the will of the people, sanctioned this arrangement in secret session, and on the 12th November authorised their agent to conclude the treaty. As the Spanish expedition would thus be set free to act against Mexico, Venezuela, or New Granada, or to reinforce the Government of Peru, this was an act of treachery to the programme of the revolution and a desertion of the cause of America.