The war conflict in Eastern Ukraine started in 2014 and it is still far from its resolution. One of the most debated questions during all those years was the following: Who joined anti-Kyiv armed groups during the first years of the Donbass war, and why? Some experts claimed that Russian soldiers and paid volunteers constituted the majority of irregular anti-Kyiv forces. Others that observe the civil war find that it was Donbass locals who joined armed groups in the first place. In this presentation, based on interviews with combatants and observations collected in 2016-2017 in Moscow, St. Petersburg, Donetsk and Luhansk, Natalia Savelyeva will discuss mobilization trajectories of anti-Kyiv combatants, different factors which impacted their decision to join the fight, and the role of ideology in the Donbass war.