Croatian Air Force Day, observed in Croatia every December 12, commemorates the establishment of the Croatian Air Force in its modern form in December 1991. This day honors the accomplishments of the Croatian Air Force and Air Defense, which is one of the three main branches of the Armed Forces of the Republic of Croatia. The origins of the air force date back to World War I, with Croatian pilots serving in the Austrian-Hungarian Empire's air force, and it later operated under the Independent State of Croatia during WWII. The modern Croatian Air Force began with limited resources during the Croatian War of Independence, ultimately contributing to the country's victory. Celebrations typically include official speeches, solemn ceremonies, air shows, exhibitions, and "open days" at air bases, showcasing the capabilities and history of the air force. Currently, the Croatian Air Force has about 2,000 active personnel and over 60 aircraft.