Romanian National Unity refers to the historical and cultural process that led to the unification of various Romanian territories into a single nation-state. This process culminated in the year 1918, when the regions of Transylvania, Bessarabia, and Bukovina joined the Kingdom of Romania, significantly expanding its territory and population. The idea of national unity was fueled by a shared language, culture, and history among the Romanian people. It played a crucial role in shaping modern Romania's identity and is celebrated annually on December 1, known as National Day, commemorating the unification of Transylvania with the rest of the country.