On his arrival at Nantes, Louis XIII learned that Soubise was endeavouring to establish himself in the Île de Rié, a maritime district of Lower Poitou, separated from the mainland by vast salt marshes and small rivers, which at high tide the sea rendered impassable. If the Huguenot leader were permitted to entrench himself there, it was a position from which it would be exceedingly difficult to dislodge him; but this the King resolved not to allow him time to do; and, leaving the Queen-Mother, who had fallen ill, at Nantes, like a true son of Henri IV, he marched at once upon the enemy. The Royal army consisted of from 10,000 to 12,000 men; that of Soubise from 6,000 to 7,000; but the latter had the advantage of position and seven pieces of cannon; while the attacking force was, of course, unable to transport its artillery across the marshes. The enterprise would therefore have been a hazardous one, with a watchful and resolute enemy to contend with. On this occasion, however, Soubise showed neither the vigilance of a general nor the courage of a soldier. The approach of the enemy much sooner than he had foreseen appears to have disconcerted his plans altogether, and, instead of attempting to defend the approaches to the Île de Rié, he thought only of re-embarking his troops in a squadron of vessels which he had at his disposal, and making his escape with the plunder he had collected to La Rochelle. In the afternoon of April 14, Marillac, with a small force of infantry, occupied the Île du Perrier, adjoining the Île de Rié, and early on the following morning Bassompierre was ordered by Condé to follow with the rest of the infantry. Condé then proposed that they should ford an arm of the sea “wide as the Marne,” which separated the islands of Perrier and Rié, and where at low tide, which would be at midday, the peasants had told him, the water would be only waist-deep. Bassompierre, however, protested against this, pointing out that, if the enemy offered the least opposition to their passage, the tide would rise before half the troops had crossed, and even if they were allowed to cross unopposed, they would find themselves at a great disadvantage without cavalry or cannon. He added that, apart from these considerations, he ought certainly to await the arrival of the King. “For if you defeat M. de Soubise,” said he, “he [the King] will take it ill that you have not shared the honour of the victory with him; and, if some reverse befalls you, he will blame your precipitation, and will accuse you of not having wished or deigned to wait for him.”