Dionysius I, also known as Dionysius the Elder, was a prominent tyrant of Syracuse in ancient Sicily during the 5th century BCE. He came to power around 405 BCE and ruled until his death in 367 BCE. Dionysius is known for his military prowess and expansionist policies, which helped to strengthen Syracuse as a significant power in the Mediterranean. Under his rule, Dionysius implemented various reforms, including improvements in the economy and military organization. He was also a patron of the arts and literature, fostering a cultural environment that attracted many notable figures, including the philosopher Plato. His legacy is marked by both his authoritarian rule and contributions to Sicilian culture.