The Chechnya-based Islamic International Brigade invades neighboring Dagestan.

Chechnya, officially the Chechen Republic, is a republic of Russia. It is situated in the North Caucasus of Eastern Europe, between the Caspian Sea and Black Sea. The republic forms a part of the North Caucasian Federal District, and shares land borders with Georgia to its south; with the Russian republics of Dagestan, Ingushetia, and North Ossetia–Alania to its east, north, and west; and with Stavropol Krai to its northwest.

The Islamic International Peacekeeping Brigade, also known as the Islamic International Brigade and the Islamic Peacekeeping Army, was the name of an international Islamist mujahideen organization founded in 1998. IIPB was designated a terrorist entity by the United States in February 2003.

The 1999 war in Dagestan, also known as the Dagestan incursions, was an armed conflict that began when the Chechen-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 Republic of Dagestan and the retreat of the IIPB. The invasion of Dagestan alongside a series of apartment bombings in September 1999 served as the main casus belli for the Second Chechen War.

Dagestan, officially the Republic of Dagestan, is a republic of Russia situated in the North Caucasus of Eastern Europe, along the Caspian Sea. It is located north of the Greater Caucasus, and is a part of the North Caucasian Federal District. The republic is the southernmost tip of Russia, sharing land borders with the countries of Azerbaijan and Georgia to the south and southwest, the Russian republics of Chechnya and Kalmykia to the west and north, and with Stavropol Krai to the northwest. Makhachkala is the republic's capital and largest city; other major cities are Derbent, Kizlyar, Izberbash, Kaspiysk, and Buynaksk.