Every June 4, Finland observes the birthday of Carl Gustaf Emil Mannerheim, a significant Finnish statesman and military leader. This day is also recognized as the flag day of the Finnish Defense Forces. Mannerheim, born in 1867, played a crucial role in Finland's history, serving as the commander-in-chief of Finland's army during the civil war in 1917 and later as Chief of Defense during World War II. He is often referred to as the father of modern Finland for his contributions to the country's independence. On this day, flags are flown from public buildings from 8 a.m. to sunset, and citizens honor Mannerheim's legacy as well as those who have served in the Finnish Defense Forces. The observance reflects both national pride and remembrance of Mannerheim's impact on Finland.