Jasta 4 was founded on 25 August 1916, drawing personnel from FFA 23 and other two-seater reconnaissance units within 2 Armee, as well as from Kampfeinsitzerkommando Vaux and Armee-Flugpark Nr. 2.
On 23 April 1918, Junor fell victim to German ace Egon Koepsch of Jagdstaffel 4, who shot him down at Bray-sur-Somme.