Donation of the valley to the Guevaras. According to the study carried out by Ayerbe Iríbar (Op. Cit., 580-589), the exact date of the donation document is 1370. According to her: "The words expressed in the document are not very explicit when it comes to determining the real content of the donation, and this will make D. Beltrán and his successors take the whole for the part. The document states that it gives him: "our sallinas of Léniz and our places of land in Léniz and the ironworks of Mondragón and the public scrivener's office of the said town of Mondragón", with all its rents, taxes and rights and with its meadows, pastures, exidos, running waters, manantes and estantes, entrances and exits, and with civil and criminal justice, high and low, and with mere and mixed empire, by oath of inheritance. Certain clauses are established: a) in the case of sale, pawning, donation, exchange or alienation, it may not be done with a religious or orderly person, nor with foreigners, without the express licence of the king. b) the king or his successors must be received in these places, whether high or low, night or day, with little or much, angry or calm. c) from each forge he may take 3 maravedís per quintal of iron or steel. And the authorities of the place are ordered to receive D. Beltrán, to consider him as their lord, to obey and comply with his letters and orders, to go to his summons and summons, and to pay them the taxes and rents that correspond to them". The full text of the doc. in Op. cit. pp. 587-589.