Lope de Mendoza, as already mentioned, made his escape from Arequipa with a small number of followers, and was pursued for a long way.  He for some time followed the line of the coast, and after he had eluded the pursuit of the party sent after him by Carvajal, he and his companions resolved so endeavour to penetrate into the government of Diego de Roias on the Rio Plata, as all the country of Peru had universally submitted to the domination of Gonzalo.  For this purpose Mendoza followed the same route which Centeno had formerly taken when retreating from Alfonso de Toro; both because he thought his enemies would not pursue him by that road and because the Indians belonging to Centeno and himself dwelt in that part of the country, and he expected to procure provisions and other assistance from them.  While travelling across these deserts, Mendoza met with Gabriel Bermudez, who had accompanied Diego de Roias on his expedition into the country on the Rio Plata.  From this person Mendoza was informed of the events which had occurred to the expedition under De Roias, of which the following is an abstract: 

Diego de Roias, Philip Gutierrez and Pedro de Heredia, who went upon this expedition, had to fight their way among hostile Indians, in the course of which De Roias was slain.  After his death, violent disputes arose between Francisco de Mendoza who succeeded in the command and the other officers engaged in the expedition, in the course of which Gutierrez was cashiered and banished.  They continued after this to prosecute their discoveries all the way to the Rio Plata, receiving information that great riches were to be found in some districts in the neighbourhood, in which there were certain Spaniards who had penetrated into the country by ascending the Rio Plata from the Atlantic, and had formed establishments in the interior.  In prosecuting the exploration, of that great river, they had fallen in with some forts which were built by Sebastian Gabota; and reported many other surprizing and wonderful things which they had seen in that country.  In the course of their proceedings, Francisco de Mendoza was assassinated by Pedro Heredia, owing to which violent disputes had taken place among them, by which and the smallness of their force they had been rendered unable to proceed in conquering the country, so that at length they had come to the resolution of returning into Peru, that his majesty or the viceroy of that kingdom might nominate a new commander.  They were likewise persuaded, when the riches of the country in which they had been came to be known, that they would be able to procure a considerable accession of new adventurers, so as to enable them to atchieve the conquest.