to be established in reality, and he did make one notable attempt to educate a ruler in the principles of philosophy. In 367 BC, Dionysius II came to power in Syracuse, Sicily, under the supervision of his uncle Dion, who was a friend and disciple of Plato. Dion invited Plato to Syracuse to serve as an advisor to Dionysius, and Plato accepted. However, he probably hoped for nothing more than to exercise a moderating influence on the tyrant; he is unlikely to have believed that he could transform Dionysius into a true philosopher king. In the event, Dionysius proved an unwilling student, and nothing came of the endeavor. Later, Dion attempted to seize power for himself, and was ultimately assassinated. In his possibly spurious Seventh Letter, Plato regretted Dion's death, and wrote that Other examples Many other historical figures have been put forward as potential examples of philosopher kings. According to W. K. C. Guthrie and others, Plato's friend Archytas may have been the original inspiration behind the concept. Not only was Archytas a distinguished Pythagorean philosopher, he was also a skilled military general and a popular political leader, serving seven terms as strategos in the city of Tarentum, Italy. Alexander the Great, as a student of Aristotle, has often been described as a philosopher king. His contemporary Onesicritus spoke of him as a "philosopher in arms", and the 1st-century Platonist Plutarch wrote in laudatory terms of his wisdom, generosity, temperance and courage. Plutarch's justification for calling Alexander a philosopher was that he had actualised principles which had previously only been spoken of as ideals, and had "changed the brutish customs of countless nations". However, Alexander remains a controversial figure, as various historians have portrayed him very differently even into the modern day. Roman emperor Marcus Aurelius is also frequently cited as a fulfilment of the philosopher king ideal. Ancient sources such as the Historia Augusta call him "the philosopher" and praise him for the clemency of his reign, while his Stoic tome Meditations is still revered as a literary monument to a philosophy of service and duty. Further examples include: Khosrow I (c. 512 – 579), ruler of Iran, admired in Persia and elsewhere for his character, virtues, and knowledge of Greek philosophy. Ashoka (268-232 BC), Buddhist Emperor of Maurya dynasty, India Abu Yaqub Yusuf (1135–1184), Islamic caliph and patron of Averroes. Nezahualcoyotl (1402–1472), tlatoani of the city-state of