The Tet Offensive was both a major escalation and one of the largest military campaigns of the Vietnam War. The North Vietnamese People's Army of Vietnam (PAVN) and the Viet Cong (VC) launched a surprise attack on 30 and 31 January 1968 against the forces of the South Vietnamese Army of the Republic of Vietnam (ARVN), the United States Armed Forces and their allies, targeting military and civilian command and control centers throughout South Vietnam. The name is the truncated version of the Lunar New Year festival name in Vietnamese, Tết Nguyên Đán, a holiday period when most ARVN personnel were on leave. The North Vietnamese Politburo and leader Lê Duẩn intended to trigger political instability and hoped that mass armed assaults on urban centers would trigger defections and uprisings.