Independence Day in Montenegro is observed on May 21 every year, commemorating the anniversary of the independence referendum held in 2006, where approximately 55.5% of voters supported independence from the State Union. This day is one of Montenegro's two national holidays, with the other being Statehood Day on July 13. The celebration marks the formal proclamation of Montenegro's independence, which was confirmed on May 31 and officially declared on June 3. Historically, Montenegro has a rich background, having been recognized as an independent state by the Treaty of Berlin in 1878 and becoming a kingdom in 1910. The name "Montenegro," meaning "Black Mountain," has been in use since the 15th century. During Independence Day, various ceremonies and events are likely held to honor the nation's sovereignty and history.