The advance of San Martin was not altogether unexpected by the Royalist forces, whose spies kept the Spanish commander informed of this latest move on the part of the patriot army. General San Martin, becoming aware of this, repaid these spies in their own coin. Taking them, as it seemed, into his confidence, he informed them of the route he was about to take, and when the time came chose another and a parallel pass. Hastening down the tremendous rocky walls of the western side of the Andes, San Martin engaged the Spanish forces and won an important victory at Chacabuco. The Royalists, under General Osorio, rallied and made a last desperate stand; but their forces were decisively and finally defeated on April 5, 1818, at Maipu, and this action resulted in the definite liberation of Chile. San Martin was now the hero of Chile, and was begged to accept the protectorship of the new Republic. His deeds on land were rivalled by those of Admiral Cochrane on sea. The gallant Irish sailor was at the time busily occupied in sweeping the Pacific Ocean clear of the Spanish vessels, and in performing those extraordinary feats of valour for which his memory is famed. Unfortunately, misunderstandings between the pair eventually resulted in open enmity between Cochrane and San Martin. This became accentuated when the campaign was undertaken in Peru, when San Martin, not content with his victories in Chile, led his armies for the liberation of the north into Peru itself, and into the head-quarters of the remaining Spanish power. It was in Peru, then, that the dispute between Cochrane and San Martin broke out in a public fashion. Its origin in this instance was a difference of opinion concerning the measures to be taken for the capturing of Callao Castle. The impetuous Irishman was for storming the place at once. The prudent San Martin, on the other hand, was desirous of bringing about the surrender without bloodshed. The latter had his way, but was subjected to some criticism, since a number of Royalist soldiers who escaped were enabled to carry on the campaign in the interior. The second and more violent dispute broke out on San Martin's refusal to pay the fleet out of the funds in Lima. On this Lord Cochrane took forcible possession of a large sum of money at the Port of Ancon, thus widening still further the already grave breach between the two. Once or twice, indeed, it was a mere chance which prevented an outbreak of active hostilities between the sea and land forces. Fortunately for all concerned, matters were not destined to reach such a pass. This, however, is somewhat in advance of the period with which we are dealing, and it will be necessary to return for a short while to Peru in its colonial state.