In its policy towards the Caucasus, especially towards Azerbaijan, Soviet Russia acted as the successor of Tsarist Russia. Baku was significant for the Bolsheviks not only because of its oil and exceptional economic potential but also as a political center of the entire Near and Middle East. Although the Baku Council of People's Commissars, led by the Dashnak-Bolshevik S. Shaumyan, was overthrown in 1918, the struggle for Baku always remained in focus.
      
In the spring of 1919, the Baku Bolsheviks expanded their activities against the government of the Azerbaijan Democratic Republic: they conducted propaganda among the English soldiers, achieving their demands to return home; attempts were made to "revolutionize" the Azerbaijani army and navy; military units composed of workers were formed, and their armament was intensified; ideological propaganda against the government was expanded; an ordered Armenian uprising in Karabakh was organized, laying the groundwork for a crisis in the ADR government. During this period, "self-sacrifice" for the benefit of Turkey was even demonstrated. Despite all this, the Bolsheviks were not confident that an uprising within the country could succeed without the intervention of Soviet Russia. Thus, the only serious external threat to the Azerbaijan Democratic Republic, whose independence was de facto recognized in January 1920, was the Bolshevik invasion. Therefore, the proposal of Soviet Russia to conclude a military alliance against Denikin's army was not unequivocally accepted by the Azerbaijani government and political parties. The Foreign Minister of the Azerbaijan Democratic Republic, Fatali Khan Khoyski, rejected G. Chicherin's proposal. Azerbaijani socialists and "Ittihadists" demanded a positive response to Chicherin's note. At a time of intensifying internal political struggle, Russian pressure also increased. Soviet Russia continued to send notes to the Azerbaijani government. To mask foreign intervention, the Bolsheviks began preparations for an armed uprising within the country to overthrow Azerbaijan's national government. On February 11-12, 1920, the congress of the RCP(b) Baku committee, "Hummet", and "Adalat" organizations took place. It was decided to unite all communist organizations in the country under the single name "Azerbaijan Communist (Bolsheviks) Party". The First Congress of the AC(b)P adopted a policy of forcibly overthrowing the legitimate government of the Azerbaijan Democratic Republic. However, some Bolsheviks continued to doubt the success of the armed uprising.
      
On the eve of the Soviet Russian attack, Armenian representatives who had arrived in Moscow offered their assistance in overthrowing the Azerbaijani Government in exchange for territorial concessions. Undoubtedly, the Armenian uprising in Karabakh in mid-March, planned in advance and involving the deployment of Azerbaijani troops to Karabakh, was the result of a premeditated provocation plan. In March 1920, the aim of the uprising raised against the Azerbaijan Republic in the mountainous part of Karabakh, and the aggression carried out by Armenia towards Kazakh and Nakhchivan, was to draw the regular units of the Azerbaijani army away from Baku. The suppression of the Karabakh uprising, which began with the attack of Dashnak bandit groups on the Khankendi garrison, necessitated the urgent transfer of troops from Baku and the borders of Dagestan to the mountainous part of Karabakh.
     
Alongside the external threat, the crisis deepened towards the end of March due to the government's resignation. However, since a new government was not formed, the old cabinet continued its activities for the time being. By mid-April, the concentration of Red Army units on the Azerbaijani borders had caused serious concern for the Azerbaijani Government.
     
On April 21, 1920, Directive No. 490 sent by the command of the Caucasus Front to the leadership of the 11th Red Army and the Volga-Caspian Flotilla indicated that the main forces of Azerbaijan were engaged on the western front of their state. Therefore, in the directive signed by Tukhachevsky, Orjonikidze, and Zakharov, the 11th Red Army and the Volga-Caspian Flotilla were ordered to cross the Azerbaijani border on April 27 and complete the Yalama-Baku operation within five days. On April 23, this directive was amended, and it was ordered that the final task of the 11th Red Army was not to capture the Baku governorate but to take control of all of Azerbaijan.
     
Even while the government of the Azerbaijan Democratic Republic was still in power, on the night from April 26 to April 27, a radio telegram was sent to Moscow on behalf of the Azerbaijani Provisional Revolutionary Committee requesting military assistance. Thus, the execution of the pre-planned operation for the occupation of Baku was accelerated, and the direct military intervention of the 11th Red Army, which blatantly violated international legal norms by crossing the borders of Azerbaijan, determined the fate of the Azerbaijan Democratic Republic. Faced with the accomplished fact, the Azerbaijani Parliament was forced to reconcile with reality. Under the circumstances of having aggressive foreign military forces - the units of the 11th Red Army on its territory, and under open armed pressure, the Azerbaijani Parliament on April 27, 1920, brought to the agenda the ultimatum presented by the communists on behalf of the Central Committee of the Azerbaijan Communist (Bolsheviks) Party, the Central Committee of the Russian Communist Party (Bolsheviks) Caucasian Bureau, and the Baku Workers' Conference and, after heated discussions, around 11 p.m., decided to hand over power to the Azerbaijan Revolutionary Committee under the following conditions:  1) The Russian army will head directly to Anatolia by rail without entering Baku;  2) The independence and territorial integrity of Azerbaijan will be protected from any aggression and annexation; 3) The Azerbaijani army will not be disbanded; 4) The freedom and independence of Azerbaijan's political parties will be safeguarded; 5) No former state officials, government members, or parliamentarians will be accused of political crimes, the jobs of state institution employees will be retained, only leadership positions will be changed; 6) Azerbaijani councils, assembled in free conditions, will determine the form of government authority.
      
As soon as the Azerbaijani delegation at the Paris Peace Conference learned of the overthrow of the Republic, it submitted a note to the San Remo Conference on April 28 about this event. However, neither this nor subsequent appeals yielded any results. Despite only lasting for 23 months, the Azerbaijan Democratic Republic, which holds a special place in the statehood history of the Azerbaijani people, fell.

Recommended literature:

1. Yaqublu, Nəsiman Qara oğlu. Türkiyənin azərbaycanlılara müstəqillik mücadiləsində dəstəyi : Sovetlər dönəmi: 1920-1991-ci illər / N. Q. Yaqublu ; elmi red. S. R. Məmmədli. - Bakı : Abşeron Nəşr, 2009. - 196 s.
2. Cabbarov, Fərhad Rafiq oğlu. Hədəf - Bakı: "Qara qızıl" uğrunda mübarizə: 1917-1922 / F. R. Cabbarov.- Bakı: Alatoran yayınları, 2021.- 242 s. 
   Həsənov, Həsən Əziz oğlu. Birinci respublikaya aparan yolda: 1917-ci ilin fevralından 1918-ci ilin mayına qədər / H. Ə. Həsənov; rus dilindən tərc. M. Süleymanov; elmi red., ön sözün müəl. İ. S. Bağırova; AMEA A.A. Bakıxanov adına Tarix İnstitutu.- Bakı: TEAS Press, 2018.- 448 s.
3. Qəniyev, Həsən Qərib oğlu. Azərbaycan Xalq Cümhuriyyəti - 100 il: 28 may 1918-ci il - 27 aprel 1920-ci il / H. Q. Qəniyev, E. Talışınski; elmi red. A. İskəndərov; Bakı İslam Universiteti.- Bakı: Mütərcim, 2018.- 80 s.
4. Rəhimov, Emil. Azərbaycan: Müsəlman Şərqində ilk demokratik Respublikanın yaranmasının 100 illiyi / E. Rəhimov.- Bakı: Şərq-Qərb, 2018.- 144 s.
5. Каземзаде, Фируз. Борьба за Закавказье: 1917-1921 / Ф. Каземзаде; пер. А. Умаевой; Институт Стратегических Исследований Кавказа.- Стокгольм: CA&CC Press, 2010.- 328 с.
6. Азербайджанская Демократическая Республика: 1918-1920 / Институт Истории АН Азербайджанской ССР; редкол. Ф. Максудов [и др.]; отв. ред. Н. Агамалиева.- Баку: Элм, 1998.- 316 с.