Campaign Z (17 December 1971 – 30 January 1972) was a military offensive by the People's Army of Vietnam; it was a combined arms thrust designed to defeat the last Royal Lao Army troops defending the Kingdom of Laos. The Communist assault took Skyline Ridge overlooking the vital Royalist base of Long Tieng and forced the restationing of Royalist aviation assets and civilian refugees. However, Communist forces eventually receded back onto their lines of communication without capturing the base.