But Azurara was too valuable a man to be allowed to spend his whole time and energy in the routine work of an office; and so we find that when the King had reigned twenty years or more, which would be in or about 1458, he commissioned him to relate the history of Ceuta under the Governorship of D. Pedro de Menezes, to whom the city had been entrusted on its capture.[36] The story runs, that for some time João I was unable to meet with anyone who would undertake the responsibility of guarding the new conquest, and, word of this having been brought to D. Pedro while he was playing at "Chóca", he at once hastened into the King's presence, and said he would engage to hold the city against the whole strength of Africa with the olive-wood crook he had just been wielding.[37] Be this incident true or not, certain it is that D. Pedro de Menezes succeeded in maintaining Ceuta, despite all the efforts of the Moors to expel him; and his achievements, as chronicled by Azurara, form by themselves sufficient ground for Affonso's commission. But another reason, no doubt, influenced the King, and that was the supreme importance attached to the possession of the old city. Its position as the key of the Straits enabled the Portuguese to hinder the Moorish corsairs from raiding the Algarve, and, at the same time, to help the Christian cause by attacks on the last relic of Mohammedan power in the Peninsula, the kingdom of Grenada. Added to this, its conquest was hailed as the first step in the realisation of that cherished ideal, an African Empire: for, besides being a great trading centre and the sea-gate of Mauritania, it formed a wedge driven into the heart of the Infidel, and a fitting crown to the struggle of seven centuries, which, commencing on the morrow of the battle of the Guadalete, had ended by the establishment of the Cross in the land of the Crescent. The tide had turned at last and for ever, and the Gothic monarchy was avenged. [Footnote 36: _Chronica do Conde D. Pedro de Menezes_, ch. 1.] [Footnote 37: "Chóca" is an old-fashioned Portuguese game played with a stout staff and ball. The incident is referred to by Camöens in _Eclogue I_, in the lines beginning, "Emquanto do seguro azambugeyro", etc.] Azurara, who on previous occasions had proved himself a ready writer, compiled the _Chronica do Conde D. Pedro de Menezes_ more slowly, owing doubtless to the fact that his new official duties kept him from devoting his whole time to the work, and the Chronicle was not finished until 1463.