The Dagestan War (Russian: Дагестанская война), also known as the Invasion of Militants in Dagestan (Russian: Вторжение боевиков в Дагестан) began when the Chechnya-based Islamic International Peacekeeping Brigade (IIPB), an Islamist group, led by Shamil Basayev, Ibn al-Khattab, Ramzan Akhmadov and Arbi Barayev, invaded the neighboring Russian republic of Dagestan, on 7 August 1999, in support of the Shura of Dagestan separatist rebels. The war ended with a major victory for the Russian Federation and Dagestan Republic, and the retreat of the IIPB. The invasion of Dagestan served as the main casus belli alongside the series of apartment bombings in September 1999 for the Second Chechen War.