Spanish volunteers served in 15. (span.) Staffel June 1942 - February 1944, nicknamed the Escuadrilla Azul ("Blue Squadron").

Commanders

Oberst Theo Osterkamp (19 Sep 1939 - 23 July 1940)
Oberstleutnant Werner Mölders (23 July 1940 - 19 July 1941)
Oberstleutnant Friedrich Beckh (19 July 1941 - 10 Apr 1942)
Oberstleutnant Karl-Gottfried Nordmann (10 Apr 1942 - 30 Mar 1944)
Major Fritz Losigkeit (1 Apr 1944 - 31 Mar 1945)
Major Heinz Lange (31 Mar 1945 - 8 May 1945)

Honor title

In the post-war Luftwaffe, the honour title Mölders lived on, on 22 November 1973 Jagdgeschwader 74 was given the title Jagdgeschwader 74 Mölders by Inspekteur der Luftwaffe Generalleutnant Günther Rall. The members of this unit wore a "Geschwader Mölders" cuff-title.
It lost the honour title 11 March 2005 following a decision by the Ministry of Defence published on 28 January.

Notable members

Hermann Graf (The first fighter ace to achive 200 victories, holder of the Knight's Cross with Oak Leaves, Swords and Diamonds)
Werner Mölders (The first pilot to score 100 victories, Holder of the Knight's Cross with Oak Leaves, Swords and Diamonds, the post-WW2 Luftwaffe unit Jagdgeschwader 74 Mölders was named in his honour 1973-2005 as was the Bundesmarine destroyer D186 Mölders)
Theodor "Theo" Osterkamp (WW1 ace with 32 victories who won six more during WW2)

Insignia

The "Jagdgeschwader Mölders" cuff title was authorized for this unit 20 Dec 1941.

Spanish volunteers taking the oath in 1941

(Courtesy of Die Deutsche Wochenschau/Ivan)

Sources used

Research by Gareth Collins
Gordon Williamson & Thomas McGuirl - German military cuffbands 1784-present

Reference material on this unit

Jorge Fernández-Coppel - La Escuadrilla Azul: Los pilotos españoles en la Luftwaffe
Santiago Guillén & Carlos Caballero - Escuadrillas Azules en Rusia
Franz Kurowski - Oberstleutnant Heinz Bär: Als Jagdflieger an allen Fronten