The first time a manned VTOL capable aircraft lifted vertically from the ground. The aircraft reached an altitude of 0.6 metres (2.0 ft) although it was extremely unstable and needed to be steadied by four assistants on the ground.
This was also the first multi-rotor rotorcraft (a quadcopter).

Source: "Milestones of Flight", Michael J.H. Taylor & David Mondey, Jane’s Publishing Company Limited, 1983, Page 24