Tsar Ferdinand I was the ruler of Bulgaria from 1887 to 1918. He was born on February 26, 1861, and became known for his efforts to modernize the country and strengthen its military. Ferdinand played a significant role in Bulgaria's participation in the Balkan Wars and World War I. During his reign, Ferdinand I faced various challenges, including political instability and economic difficulties. In 1918, after Bulgaria's defeat in World War I, he abdicated the throne in favor of his son, Boris III. Ferdinand's legacy includes his contributions to Bulgaria's national identity and development during a tumultuous period.