During the Second Chechen War, the Yamadayevs and Akhmad Kadyrov arranged for their stronghold of Gudermes to be taken over by federal forces without a fight. Later, Sulim became leader of the GRU Spetsnaz unit called the Special Battalion Vostok ("East") of nearly 600 men, succeeding his brother Dzhabrail Yamadayev following his assassination in 2003. While working closely with the General of the Army Alexey Maslov, Sulim Yamadayev received the medal and title of Hero of the Russian Federation after his Vostok battalion killed the commander of the Arab Mujahideen in Chechnya, Abu al-Walid, in April 2004. Together with his paramilitary soldiers known within Chechnya as "Yamadayevtsy", which are alleged to be unruly and prone to mix warfare with crime, Yamadayev often conflicted with Ramzan Kadyrov (the son of Akhmad) and Said-Magomed Kakiyev over who controls overall military authority in Chechnya. Isa and Badrudi, the younger brothers of Sulim, became the company commanding officers in the battalion.