At the end of three years, in 1564, he left the university. The following year was that of the famous siege of Malta; and all Christendom hung in suspense on the issue of the desperate conflict, which a handful of warriors, on their lonely isle, were waging against the whole strength of the Ottoman empire. The sympathies of Don John were roused in behalf of the Christian knights; and he resolved to cast his own fortunes into the scale with theirs, and win his maiden laurels under the banner of the Cross. He did not ask the permission of his brother. That he knew would be refused to him. He withdrew secretly from the court, and with only a few attendants took his way to Barcelona, whence an armament was speedily to sail, to carry succour to the besieged. Everywhere on the route he was received with the respect due to his rank. At Saragossa he was lodged with the archbishop, under whose roof he was detained by illness. While there he received a letter from the king, who had learned the cause of his departure, commanding him to return, as he was altogether too young to take part in this desperate strife. Don John gave little heed to the royal orders. He pushed on to Barcelona, where he had the mortification to find that the fleet had sailed. He resolved to cross the mountains and take ship at Marseilles. The viceroy of Catalonia could not dissuade the hot-headed youth from his purpose, when another despatch came from court, in which Philip, in a more peremptory tone than before, repeated his orders for his brother to return, under pain of his severe displeasure. A letter from Quixada had warned him of the certain disgrace which awaited him, if he continued to trifle with the royal commands. Nothing remained but to obey; and Don John, disappointed in his scheme of ambition, returned to the capital.[146] This adventure caused a great sensation throughout the country. The young nobles and cavaliers about the court, fired by Don John's example, which seemed like a rebuke on their own sluggishness, had hastened to buckle on their armour, and follow him to the war.[147] The common people, peculiarly sensible in Spain to deeds of romantic daring, were delighted with the adventurous spirit of the young prince, which gave promise that he was one day to take his place among the heroes of the nation. This was the beginning of the popularity of John of Austria with his countrymen, who in time came to regard him with feelings little short of idolatry. Even Philip, however necessary he may have thought it to rebuke the insubordination of his brother, must in his heart have been pleased with the generous spirit he had exhibited. At least, the favour with which he continued to regard the offender showed that the royal displeasure was of no long continuance.