The 1st SS Infantry Brigade was a Waffen-SS brigade of Nazi Germany that was active from April 1941 to January 1944. The brigade was formed from former concentration camp guards for service in the Soviet Union behind the main front line during World War II, and they conducted anti-partisan operations in the rear of the advancing Wehrmacht and were involved in the Holocaust. The 1st Brigade filled in gaps in the front line in the case of emergencies, and it was used as the cadre in the formation of the 18th SS Volunteer Panzergrenadier Division Horst Wessel in 1944.