Some background

The unit was led by Andriy Biletsky, who served as the the leader of both the Patriot of Ukraine (founded in 2005) and the SNA (founded in 2008). The SNA is known to have carried out attacks on minority groups in Ukraine. In 2010, Biletsky said Ukraine’s national purpose was to “lead the white races of the world in a final crusade … against Semite-led Untermenschen [inferior races]”. Biletsky was elected to parliament in 2014. He left Azov as elected officials cannot be in the military or police force. He remained an MP until 2019. The 42-year-old is nicknamed Bely Vozd – or White Ruler – by his supporters. He established the far-right National Corps party in October 2016, whose core base is veterans of Azov.

A little more (bear in mind, this is lifted straight from wikipedia so probably whitewashed, but still):

The S.N.A. was founded in 2008 and maintained relations with the wider social-nationalist movement in Ukraine. In the late 2000s, Ukrainian president Victor Yushchenko and the Our Ukraine bloc bolstered the S.N.A. and other far-right groups by supporting an explicitly nationalist view of Ukrainian history. Following the 2009 death of Maksym Chaika, an S.N.A member who was killed in a fight with antifascists in Odessa, Yushchenko supported the far-right interpretation of Chaika's death, describing him and others as heroes and victims driven to violence for a just cause. In 2010, the Ukrainian Helsinki Human Rights Union reported on attacks by the S.N.A and "Patriot of Ukraine" against Vietnamese and other foreign market stalls in Vasylkiv. Most attacks were carried out by youth and targeted Vietnamese, Uzbeks and Gypsies. According to the S.N.A website, they drove foreigners from the market within two weeks and replaced them with Ukrainians. The S.N.A states that some of their victims were hospitalized. Later that year, Ukrainian authorities shut down an S.N.A music festival near Kyiv that promoted neo-Nazism and chauvinism among Ukrainian youth. The music glorified the skinhead movement, Nazi aesthetics and the harassment of minorities. In August 2011, the Netherlands Institute of Human Rights warned about the growth of extremist organizations including the S.N.A and "Patriot of Ukraine", noting repeated attacks against foreigners and visible minorities. The institute also noted the government's inability or unwillingness to deal with extreme-right movements in Ukraine.

In 2013, the S.N.A, "Patriot of Ukraine" and Autonomous Resistance all increased in popularity, contributing to the growth of Svoboda as well. The Social National Assembly helped to create an umbrella radical organization - the Right Sector (Pravy Sector). Other openly radical anti-semitic groups operating in Ukraine including the "White Hammer" and "C14", a neo-Nazi wing of Svoboda, joined it. During the 2014 Ukrainian revolution, the militants from the S.N.A and the "Patriot of Ukraine" were on the front lines of the street riots in Kyiv. According to Igor Krivoruchko, the leader of the Kyiv's S.N.A. branch, its members started clashes with the police near the Presidential Administration Building (Kyiv) and also initiated the Hrushevskoho Street riots. They seized and burned on 18 February 2014 the central office of the ruling party - the Party of Regions - in Kyiv. A bystander, 57-year-old IT engineer who tried to stop the attackers from entering the server room, was beaten to death. Oleh Odnoroshenko, the S.N.A and "Patriot of Ukraine" ideologue and also one of the "Right Sector" leaders, stated in February 2014 that the "Right Sector" would be hesitant to enter into the government following the departure of Viktor Yanukovych. Odnoroshenko thought that the politicians would try to use the Right Sector credibility and popularity while pursuing their own agendas.

At the end of April 2014, S.N.A members marched with burning torches to the Independence Square and came into conflict with the Self-defense of the Maidan units. During the fight, the S.N.A. and Self-defense of the Maidan activists used rubber bullet guns and tear gas, and ambulances later arrived to treat wounded. Oleh Odnoroshenko volunteered to the press that the S.N.A members organized the attack on the Russian embassy in Kyiv on 14 June 2014.

In March 2014 the Social-National Assembly created a volunteer group, Azov Battalion. In April, members were wounded in combat against separatists in eastern Ukraine. During the first week of May, Kyiv granted it official status and began delivering weapons. On 6 May, the Azov Battalion captured Donetsk People's Republic defense minister Igor Kakidzyanov. The next day the S.N.A. announced that it was interrogating the captive, and Radical Party (Ukraine) leader Oleh Lyashko posted photographs of him naked and bound. Lyashko confirmed that Azov had captured Kakidzyanov and some other separatist leaders. On 13 June, the Azov Battalion stormed separatists' barricades in Mariupol and seized control of the city center after a six-hour battle.