Grigoriev and Makhno
In July 1919, after suffering heavy losses against Red Army Grigoriev escaped to the areas controlled by Nestor Makhno and offered to join the forces against "the reds and the whites". His proposition was accepted.
Makhno and the Black Army did not trust Grigoriev. After 3 weeks of common actions against Bolshevik forces, Grigoriev openly disagreed with Makhno during negotiations at Sentovo on July 27, 1919 (today it is a village of Rodynkivka, Oleksandriv Raion, Kirovohrad Oblast). Grigoriev had been in contact with Denikin's emissaries, and was planning to join the White coalition. This was unacceptable to Makhno — he held a particular hatred of all monarchists and aristocrats since the time of his imprisonment. The White coalition (notably generals Shkuro and Krasnov) also shared Grigoriev's anti-Semitism, unacceptable to Makhno and his numerous Jewish aides. According to Peter Arshinov, Makhno and staff decided to execute Grigoriev. Chubenko, a member of Makhno's staff, accused Grigoriev of collaborating with Denikin (According to Arshinov, Denikin's emissaries were captured and executed) and of inciting the pogroms. There are several accounts that give different circumstances of Grigoriev's death. Grigoriev threatened Chubenko and Makhno, drew his gun, and was shot and killed. The accounts of the event differ, and ascribe the final shot either to Chubenko, Karetnik or Makhno.
Read more about this topic: Nikifor Grigoriev