During this reign, the Romans were carrying on a war with Mithridates, King of Pontus, in Asia Minor; and Sulla, who was then at the head of the republic, sent Lucullus, the soldier, the scholar, and the philosopher, as ambassador to Alexandria, to ask for help against the enemy. The Egyptian fleet moved out of harbour to meet him, a pomp which the kings of Egypt had before kept for themselves alone. Lathyrus received him on shore with the greatest respect, lodged him in the palace, and invited him to his own table, an honour which no foreigner had enjoyed since the kings of Egypt had thrown aside the plain manners of the first Ptolemies. Lucullus had brought with him the philosopher Antiochus of Athens, who had been the pupil of Philo, and they found time to enjoy the society of Dion, the academic philosopher, who was then teaching at Alexandria; and there they might have been seen with Heraclitus of Tyre, talking together about the changes which were creeping into the Platonic philosophy, and about the two newest works of Philo, which had just come to Alexandria. Antiochus could not read them without showing his anger: such sceptical opinions had never before been heard of in the Academy; but they knew the handwriting of Philo, they were certainly his. Selius and Tetrilius, who were there, had heard him teach the same opinions at Rome, whither he had fled, and where he was then teaching Cicero. The next day, the matter was again talked over with Lucullus, Heraclitus, Aristus of Athens, Ariston, and Dion; and it ended in Antiochus writing a book, which he named Sosus, against those new opinions of his old master, against the new Academy, and in behalf of the old Academy. Lathyrus understood the principles of the balance of power and his own interest too well to help the Romans to crush Mithridates, and he wisely wished not to quarrel with either. He therefore at once made up his mind not to grant the fleet which Lucullus had been sent to ask for. It had been usual for the kings of Egypt to pay the expenses of the Roman ambassadors while living in Alexandria; and Lathyrus offered four times the usual allowance to Lucullus, beside eighty talents of silver. Lucullus, however, would take nothing beyond his expenses, and returned the gifts, which were meant as a civil refusal of the fleet; and, having failed in his embassy, he sailed hastily for Cyprus, leaving the wonders of Egypt unvisited. Lathyrus sent a fleet of honour to accompany him on his voyage, and gave him his portrait cut in an emerald. Mithridates was soon afterwards conquered by the Romans; and it was only by skilful embassies and well-timed bribes that Lathyrus was able to keep off the punishment which seemed to await him for having thus disobeyed the orders of Sulla. Egypt was then the only kingdom, to the west of Persia, that had not yet bowed its neck under the Roman yoke.