They promise to return the old Navarrese territories, 1366-1367. Pedro I, dethroned, desperately tries to secure Navarrese friendship. To this end he promised at Livourne on 23 September 1366 the restoration to the kingdom of Navarre forever of "the lands of Guip, with the enclosed and chartered towns of Tolosa, Segura, Mondragón, Oyarzun, Fuenterrabia, San Sebastián, Guetaria and Motrico, with all the other castles and with all the rights that the land of Guip should have in Spain, and also the towns of Vitoria, Salvatierra, Alfaro, Navarrete, Logrono, Fitero, Tudug n and Calahorra, with their castles and villages, and he ordered their inhabitants to recognise D. Carlos as their king. At the same time, to further oblige D. Carlos to the alliance of D. Pedro, the prince of Wales, his protector, he promised this one, from San Melián, on 27 September 1366, to the kingdom of Navarre, of the lands of Guip, with the enclosed and chartered towns of Tolosa, Segura, Mondragón, Oyarzun, Fuenterrabia, San Sebastián, Guetaria and Motrico, with all the other castles and with all the rights that the land of Guip should have in Spain, and also the towns of Vitoria, Salvatierra, Alfaro, Navarrete, Logrono, Fitero, Tudug n and Calahorra, with their castles and villages, and he gave orders to their inhabitants to recognise D. Carlos as their king. At the same time, to further oblige D. Carlos to the alliance of D. Pedro, the prince of Wales, his protector, he promised this one, from San Melián, on 27 September 1367, to the kingdom of Navarre, of the lands of Guip, with the enclosed and chartered towns of Tolosa, Segura, Mondragón, Oyarzun, Fuenterrabia, San Sebastián, Guetaria and Motrico, with all the other castles and with all the rights that the land of Guip should have in Spain, and also the towns of Vitoria, Salvatierra, Alfaro, Navarrete, Logrono, Fitero, Tudug n of the same month of September, that he would respect the cession made by Don Pedro "The Cruel" and that he would not occupy any castle or place when the prince came with his people to help Don Pedro against Don Enrique. The prince d that he had three sons of King Don Pedro as ages for the fulfillment of what he had promised those of England and Nav. (Yanguas: Dictionary ...)". Enrique de Trastamara wanted to alleviate the threat that had been hanging over him since the affair at Livourne; he also promised in the interview held with Don Carlos in Santa Cruz de Campezo (January 1367) the restitution of these patrimonial lands of the Basque kingdom. In November of this year, Pedro IV of Aragon entered into this double game; on the 21st of this month, both monarchs agreed to announce their aid to Pedro I of Castile and then do the same with Trastamara. The circumstances were dangerous for both kingdoms involved in the fratricidal war; the double game was an obligatory practice.