14 March - Act III of 1921 passed by the National Assembly. The so-called "order law" invests powers in the government to protect the social order against communists and other radicals[1]
27 March - Easter Crisis: Charles IV returns to Hungary at Szombathely
28 March - Easter Crisis: Charles IV negotiates with Horthy in Budapest. Horthy refuses to resign power. Charles IV returns to Szombathely.[2]
April
1 April - Easter Crisis: People's Assembly supports Horthy against Charles IV[3]
5 April - Easter Crisis: Charles IV leaves Hungary[4]
6 April - Act III of 1921 comes into effect
14 April - István Bethlen replaces Pál Teleki in government[5]
23 April - Romania signs alliance with Czechoslovakia[6]
May
4 May - Land swap agreement between Romania and Czechoslovakia[7]
June
7 June - Romania signs alliance with Kingdom of Serbs, Croats and Slovenes[6]
August
6 August - Inter-Allied General Committee publishes the plan for the transfer of Burgerland from Hungary to Austria in 3 stages (A, B and C Zone).[8]
9-10 August - Pact between Czechoslovakia and Austria. Czechoslovakia would support Austrian territorial claims and LoN loan, Austria denounces Habsburg restoration attempts.[1]
14 August - Serbian–Hungarian Baranya–Baja Republic declared
21 August - Serbian–Hungarian Baranya–Baja Republic dissolved
15 September - Italian foreign minister Pietro Tomasi Della Torretta begins to mediate between Austria and Hungary[11]
16 September - Prónay briefly arrests Antal Lehár[12]
23 September - Entente demands Hungary evacuate Zone B and C[11]
29 September -
Gyula Gömbös writes to Prónay, asking him to take control of Zone B and C after Hungarian evacuation.[13]
Ludwig III of Bavaria arrives to Sárvár where he spends his last weeks[14]
October
3 October - Hungarian forces leave Zone B and C.[15]
4 October - Pál Prónay declares the independent state of Lajtabánság in Burgerland
7 October - Austro-Hungarian negotiations begin in Venice with Italian mediation[16]
13 October - Venice Agreement between Hungary and Austria
17-18 October - Legitimists plot a coup against Horthy in west Hungary[14]
20 October - Charles IV returns to Hungary for the second time via airplane landing at Dénesfa at the Cziráky estates[17]
22 October - 04:30 - Telegraph notifies the Government about Charles IV's return[18]
23-24 October - Battle of Budaörs, Charles IV halted before entering Budapest
24 October - Czechoslovakia and Kingdom of Serbs, Croats and Slovenes issue an ultimatum to Hungary to resist and overthrow the Habsburgs, threaten military intervention.[19]
25 October - II. Army of Lajtabánság under Miklós Budaházy enters the Sopron plebiscite zone with 400 men and overthrows the legitimist government.[20]
27 October - 6/II Infantry Battalion replaces paramilitaries in Sopron[20]
31 October - Prónay and his officers summoned to Horthy in person, ordered the evacuation of Lajtabánság by 5 November[21]
November
1 November - Charles IV leaves Hungary for the last time
5 November - Rongyos Gárda leaves Burgerland, Lajtabánság dissolved
6 November - The People's Assembly dethrones the House of Habsburg-Lorraine (1921:XLVII Act)[22]
11 November - Inter-Allied General Committee, after notified by Hungary that the paramilitaries were evacuated, orders Austria to take control of Burgerland, except for the Sopron plebiscite zone.[23]
13-15 November - Austria takes over North Burgerland (north of Sopron)
19 November - Charles IV arrives to Madeira
25-29 November - Austria takes over Central and South Burgerland (south of Sopron)
December
2 December - Austrian, Hungarian and Entente authorities sign a protocol on the completed handover of Burgerland.[24]
14-16 December - Sopron Plebiscite: Sopron votes to stay in Hungary[25]
15-16 December - Czechoslovakia and Austria sign a pact of friendship and co-operation[1]
20 December - Council of Ambassadors accepts the result of the plebiscite[26]
22 December -
Bethlen-Peyer Pact between the Bethlen Government and the Social Democratic Party[27]
1921:LIII. Act, establishment of levente organisations[9]
23 December - Amnesty for political prisoners sentenced below 5 years[28]