In this letter, however, he but half expresses the cause of his hatred to Avignon; for he does not allude to Laura, while it was the memory of her that not only made him fly the city in which she lived, but tremble at the mere thought of how near he still was. And while he describes the heavenly tranquillity of his seclusion, and the beauty that adorned it, he exclaims, "But the vicinity of Avignon poisons all." So deep was his fear of reviving his passion by seeing its object, that he never even visited that city for a few days. On one occasion, hearing that his friend, William da Pastrengo, had arrived there, he repaired thither instantly to see him: but, on his arrival within the precincts of the fatal walls, he felt his chains fall so heavily around him, that, resolved to cast them off at once, without tarrying an hour, without seeing his friend, the same night he returned to Vaucluse, and then wrote to excuse himself; alleging, as his motive, his desire to escape from the net of passion that enveloped him in that town. At the same time, with the contradictory impulses of a lover, he entreated the painter, Simon Memmi, a pupil of Giotto, just arrived in Provence, and in high esteem with the pope and cardinals, to execute for him a small portrait of Laura.[42] Simon consented; and was so pleased with the model thus presented him, that he frequently afterwards introduced her face into his pictures of saints and angels. Petrarch repaid his friend's complaisance by two sonnets of praise and commendation. In the imaginary conversations which Petrarch pictures himself to have held with St. Augustin, the saint tells him that he is bound by two adamantine chains--love and glory. To free himself from the first of these he had retreated to Vaucluse, and found the attempt vain. The second passion of his soul became even more strong, allying itself to the first, for he wished Laura's lover to be renowned. This was also more successful, as, beside the honour in which he was held by all who knew him, it proved that his name was heard in distant countries, and his merit acknowledged. [Sidenote: 1340. Ætat. 36.] He had before entertained a vague wish for the laurel crown of poetry; but it was beyond his hopes, when, on the same day, the 24th of August, 1340, while at Vaucluse, he received letters from the Roman senate, and from the chancellor of the university of Paris, inviting him to receive it. Hesitating to which city to yield the preference, he wrote to ask the advice of cardinal Colonna; and, counselled by him, as well as following his own predilection, decided in favour of Rome.