The Montgolfier brothers demonstrated in 1783 that a light envelope filled with hot air could rise stably, first with unmanned models in Annonay and then with animals in Versailles. On 21 November 1783, Pilâtre de Rozier and the Marquis d'Arlandes made the first free, untethered human flight, over Paris. The balloon belongs to the lighter-than-air branch, not fixed-wing flight, but its historical importance is decisive: it turns flight into a public, verifiable practice.