The National anthem of the Kingdom of Yugoslavia (Kingdom of Serbs, Croats and Slovenes 1918–1929) was created in December 1918 from the national anthems of the Kingdom's main three constituent historical provinces: Croatia, Serbia and Slovenia. In those times the official authorities considered the three nations, Croats, Serbs and Slovenes as one nation with three names. The official language was thus called the Serbo-Croato-Slovene language. Although a law on the national anthem did not exist, the anthems of all three South Slavic nations were unified into a single anthem of the Kingdom. It started with a few measures from the Serbian anthem "Bože pravde", continued with a few lines from the Croatian anthem "Lijepa naša domovino", which were in turn followed by a few lines from the traditional Slovenian anthem "Naprej zastava slave". The anthem finished with some lines from the Serbian anthem again. It was officially used between 1919 and 1941. There was no official document that declared the anthem invalid, or void. The Constitution of the Kingdom of Yugoslavia was not in effect after the April capitulation.