Birthday of Cyrus the Great, Shahrivar 4. This date marks the birthday of Cyrus the Great, the founder of the Achaemenid Empire, in the Jalali calendar. Cyrus the Great lived in the 6th century BCE and established one of the largest empires of the ancient world, playing a significant role in the history of Iran and the region. Today, this day is observed as a time to reflect on the historical and cultural legacy of Cyrus the Great. Many Iranians and those interested in ancient history use Shahrivar 4 to revisit his political and social achievements and to highlight his influence on the formation of Iranian national identity.