What is Kingdom of Romania?
{{Infobox country | conventional_long_name = Kingdom of Romania {{small|{{nobold|(1881–1947)}}<br />{{big|{{nobold|''Regatul României''}}}}}}<hr />National Legionary State {{small|{{nobold|(1940–1941)}}<br />{{big|{{nobold|''Statul Național Legionar''}}}}}} | era = [[Belle Époque]]{{*}}[[World War I]]{{*}}[[Interwar period]]{{*}}[[World War II]] | event_start = [[United Principalities of Moldavia and Wallachia#History|Kingdom proclaimed]] | year_start = 1881 | date_start = 14 March | event1 = [[Treaty of Bucharest (1913)|Treaty of Bucharest]] | date_event1 = 10 August 1913 | event2 = [[Treaty of Trianon]] | date_event2 = 4 June 1920 | event3 = [[1923 Constitution of Romania|Constitution adopted]] | date_event3 = 29 March 1923 | event4 = [[1938 Constitution of Romania|Constitution adopted]] | date_event4 = 20 February 1938 | event5 = {{nowrap|[[National Legionary State]]}} | date_event5 = {{nowrap|14 September 1940}} | event6 = [[Legionnaires' rebellion and Bucharest pogrom|Iron Guard rebellion]] | date_event6 = 21 January 1941 | event7 = [[King Michael's Coup]] | date_event7 = 23 August 1944 | event8 = [[Soviet occupation of Romania|Soviet occupation]] | date_event8 = 12 September 1944 | event_end = [[Socialist Republic of Romania|Republic proclaimed]] | year_end = 1947 | date_end = 30 December | p1 = United Principalities{{!}}<small>'''1881:'''</small><br>United Principalities | flag_p1 = Flag of the United Principalities of Romania (1862 - 1866).svg | p2 = Kingdom of Bulgaria{{!}}<small>'''1913:'''</small><br>Kingdom of Bulgaria | flag_p2 = Flag of Bulgaria.svg | p3 = Moldavian Democratic Republic{{!}}<small>'''1918