The eastern Ukrainian city of Donetsk was captured by pro-Russian separatists in 2014 during widespread unrest following the pro-European revolution of Dignity in the capital city of Kyiv in February. As a result, Donetsk came under the control of the Donetsk People's Republic and became its capital.
Background.
The separatist movement in the Donetsk region has been known since 2005. After Viktor Yushchenko came to power, an organization named "Donetsk Republic" appeared. It set the goal of creating the "Donetsk Federal Republic", and began to openly collect signatures for holding a referendum. Despite a ban, the organization did not stop its illegal activities, conducting jointly with the Communist Party of Ukraine and other pro-Russian movements separatist actions.
During the pro-EU Euromaidan movement, a pro-Russian opposition movement known as anti-Maidan emerged, particularly in eastern Ukraine, where there was a large Russian speaking minority.
On December 4, thirteen days after the beginning of Euromaidan, around 15,000 people gathered at a pro-Yanukovych rally in Donetsk, though many of these people were bussed into the city. 
On February 18, the revolution of Dignity began in Kyiv. On February 21, following the signing of an agreement between Yanukovych and the opposition, police guarding the government sector of Kyiv withdrew, allowing the opposition to take control. The next day, parliament voted to remove Yanukovych from office. Meanwhile, in Donetsk, a pro-Russian rally was held.
On February 28, pro-Russian activist Pavel Gubarev, leader of the Donbas People's Militia, appeared during a Donetsk city council meeting and issued an ultimatum to the council to not recognise the new Ukrainian government, which was rejected. 
Pro-Russian Protests.
On March 1, 2014, about 10,000–15,000 people gathered for a rally demanding the support of Berkut fighters who killed demonstrators in Kyiv. The participants of the rally expressed distrust of the head of the Donetsk regional state administration Andrei Shishatsky and announced the commander of the People's Defence of Donbass Pavel Gubarev as their leader. On the same day, the Donetsk City Council initiated a referendum on the status of the Donetsk region, and the initiative of the city council was supported by the Donetsk Regional Council.
At about 12:00, supporters of Pavel Gubarev were joined by activists of the separatist organization "Donetsk Republic", who, under anti-Ukrainian slogans, demanded the voluntary resignation of Andrei Shishatsky, and then moved to storm the building of the regional state administration. The protestors faced the Special Forces "Griphon" unit, who held the building for half an hour until being forced to retreat. Under the walls of the Regional State Administration, demonstrators demanded to hold a referendum on the separation of the Donbass from Ukraine. The participants of the assault lowered the flag of Ukraine from the flagpole, replacing it with a Russian flag; the flag of the Donetsk region on another flagpole was not changed by protesters.
In the evening, the Donetsk City Council, fearing the pressure of pro-Russian forces, convened an extraordinary session, which unanimously decided to hold a referendum on the region remaining a part of Ukraine. In addition, city deputies decided to grant the Russian language the status of an official language (with Ukrainian) to establish a moratorium on price increases and reduce the level of social payments. This was to create a municipal police force and recognize Russia as a strategic partner of the region. It was also recommended to the Donetsk Regional Council (together with the Luhansk Regional Council) to create a commission for the formation of the stabilization fund of the Donbass.
On March 3, pro-Russian demonstrators seized part of the building of the Donetsk Regional State Administration, where, at a meeting of the regional council, deputies elected a new chairman of the council (Andriy Shyshatsky) and supported the decision to hold a referendum on the territory of the Donetsk region on the most pressing issues for residents of the region, condemning calls for the region's separation from Ukraine. About 1,000 people with Russian tricolors (led by self-proclaimed Governor Pavel Gubarev) stormed the session hall of the regional council, causing a clash. Pavel Gubarev addressed the audience; in his speech, he called himself the "people's governor" and ordered information of representatives of the Russian media that the regional state administration in his person did not accept the central government in Kyiv. In addition, the self-proclaimed governor said that it was planned to create a "provisional government of Donbass" and self-defense forces, and it was also proposed to the leadership of the Air Force, prosecutor's office and the SBU of the region to take an oath to the "people's authorities ". Pro-Russian activists blocked the institution, preventing employees from leaving it; it was also reported that about three deputies who did not have time to leave the regional council were forced to write statements about the drafting of their deputy powers. During the seizure of the administration, unknown people attacked the head of the regional council Andrei Shishatsky, who managed to free himself from the attackers thanks to police officers and the SBU, but during other events in the administration, the internal affairs officers did not resist the activists.
On March 5, under the pretext of detecting an explosive device in the building, the police cleared the regional administration building of protesters, and the Ukrainian flag was once again hung over the building. By 16:00, about 5,000–7,000 protesters of referendum supporters had gathered under the administration, including activists of the "People's Militia of Donbas", "Russian bloc" and activists from Russia (including the former leader of the far-right organization "Shield of Moscow" Oexiy Khudyakov). At the same time, a rally of supporters of Ukraine's unity began at Svobody Square, which gathered about 7,000–10,000 protesters. Some time after the start of the rally near the building of the regional administration, protesters led by Gubarev began to storm the building; there were clashes with soldiers of internal troops and police guarding the building. As a result of clashes with the police, the supporters of the referendum once again occupied the RSA (Regional State Administration) building and hung the Russian flag over it.
After the seizure of the RSA building, the pro-Russian forces split. About a few hundred of them supported Pavel Gubarev and went to seize the building of the Main Directorate of the Treasury in the Donetsk region, first mistakenly arriving at the Financial Inspection building, then, having reached the correct building, they began its blockade. At the same time, another group of about 1,500 pro-Russian activists moved towards Freedom Square, where they got into a fight with rallying supporters of Ukraine. Some supporters of the referendum, about 200 people, remained in the RSA building.
The next day, March 6, at about 06:45, the police freed the RSA building from the protesters, detaining 70 people, and the Ukrainian flag was returned to the building. At the same time, the Security Service of Ukraine arrested Pavel Gubarev. In the evening of this day, about 200 supporters of Gubarev picketed the building of the Main Directorate of the SBU in the Donetsk region, demanding the release of their leader.
On March 13, an anti-war rally for Ukraine's unity was attacked by pro-Russian activists. Law enforcement officers and self-defense tried to protect the participants of the action, which allowed most of them to leave Lenin Square. After the retreat of the main group of supporters of the integrity of Ukraine, police officers hid members of self-defense in their bus. They surrounded the supporters of the union of the Donbass with Russia. They pierced wheels, smashed windows and threw firecrackers at the cars; tear gas was sprayed. The police managed to detain several attackers, but under pressure from the crowd they were released. According to official information, one person died from stab wounds during the fightand 10 people were hospitalized; three were taken to the neurosurgical department of the M. Kalinin Hospital. According to media reports, the death toll is 2–3 people; at least 50 people were injured.
On March 19, the Security Service of Ukraine arrested Andrei Purgin, the leader of the Donetsk People's Republic, who took part in the assaults on the RSA building on March 3 and 5.
Separatist takeover.
On April 6, pro-Russian protesters gathered in Lenin Square. After the end of the rally, around a thousand protesters marched along Artema Street to the RSA, which they began to storm. Protestors gathered in front of the building and clashed with police who guarded a barbed wire gate on the side of the building, eventually overwhelming them and breaking into the courtyard. Meanwhile, another group threw a grenade inside the building and subsequently stormed it. Despite bringing in a water canon, police were forced to withdraw from the administration, leaving it in separatist hands. There were reportedly 100 protestors occupying the RSA following the police withdrawal.
On April 7, in the session hall of the Donetsk Regional State Administration, separatists proclaimed a "declaration of sovereignty of the Donetsk People's Republic", which was proclaimed on the territory of the Donetsk region. Separatists also announced a referendum for independence to take place no later than May 11.
At around 03:32 on April 7, protesters stormed an SBU building at 62 Shchorsa street, making no clear demands. Protesters then barricaded themselves inside with barbed wire. By evening, Ukrainian forces had retaken the building.
On April 11, Arseniy Yatsenyuk, the Prime Minister of Ukraine, visited Donetsk and offered to grant the east of the country greater autonomy.
On April 12, separatists seized the Interior Ministry in Donetsk, but failed to takeover the prosecutor's office. Following negotiations, the head of the Ministry of Internal Affairs in the Donetsk region, Kostyantyn Pozhidayev, resigned. 
On April 16, separatists, some armed with machine guns, seized the city hall building at 98 Artema street. Some of these separatists came from the Kharkiv-based mixed martial arts group 'Oplot', which would later develop into the Oplot Brigade. One of the leaders of the group, Yevhen Zhylin, described the events surrounding the capture of the city hall: 
 ;templatestyles src="Template:Blockquote/styles.css" / ;Everyone hoped that it would be like in Crimea. We would turn to Russia and everything would be fine. "Oplot" was almost the only public organization that had a power block at that time. And we seized the city administration building and defended it so that no one would rob it.
At 18:00 on April 17, a pro-Ukrainian rally took place in Victory park with around 5,000 in attendance at its peak. Protestors sung the national anthem of Ukraine and waved Ukrainian flags.
On April 27, the building of the Regional State Television and Radio Company (ODTRK) was seized.
On April 28, around 2,000 people gathered in a pro-Ukrainian rally. During the rally, multiple men dressed in military fatigues and wielding baseball bats entered the crowd and began to attack protesters, who responded by lighting fireworks and firecrackers. Ukrainian riot police managed to drive away the militants ten minutes after the beginning of the attack. As a result, 14 people were injured and 5 were unaccounted for.
During May Day celebrations on May 1, a few thousand festivalgoers gathered in Lenin square before marching south along Artema street towards a registration office on Polehlykh Komunariv avenue, where they raised the flag of the DPR with no resistance. They then continued their march to a police station located on Chelyuskintsiv avenue to ensure the police's loyalty to the republic. Police agreed to work with the protestors, who arrived at around 11:20. After the Ukrainian flag was replaced with the DPR flag at the station, an announcement was made ordering protestors to attack the prosecutor's office on Henerala Antonova street to free arrested activists.
At 12:20, the crowd, calling for the prosecutor to come out, arrived at the entrance to the prosecutor's office, which was guarded by riot police armed with shields. Within three minutes of their arrival, intense fighting had broken out, with officers detonating stun grenades and releasing tear gas whilst protestors threw rocks and chanted "fascists" at the officers. Being pushed back, the police also used shotguns loaded with rubber bullets. By 12:37, the rioters had retreated due to the tear gas. During this pause in fighting, injured officers were evacuated.
Meanwhile, the rioters moved north to attack the courtyard of the building, throwing petrol bombs at the police, who formed a testudo formation, though, by 12:56, protestors had surrounded the police the formation, which surrendered and was disarmed. An armoured personnel carrier was sent to attempt to relieve the siege