J. L. Runeberg, or Johan Ludvig Runeberg, was a Finnish poet born on February 5, 1804, in Jakobstad, Finland. He is best known for his contributions to Finnish literature and is celebrated as the national poet of Finland. His works often reflect themes of nature, love, and Finnish identity, and he wrote primarily in Swedish. Runeberg's most famous work is the poem collection titled "Fänrik Ståls Sägner," published in 1848. This collection includes poems that honor the Finnish War of 1808-1809 and has played a significant role in shaping Finnish nationalism. His legacy is commemorated annually on Runeberg's Day, celebrated on February 5.