The Estnische SS-Freiwilligen Brigade was formed when Estnische SS-Legion was upgraded in May 1943.
It was redesignated 3. Estnische SS-Freiwilligen-Brigade in October 1943.

Commander

SS-Obersturmbannführer Franz Augsberger (? May 1943 - 22 Oct 1943)

Sources used

Christopher Ailsby - Hitler's Renegades: Foreign nationals in the service of the Third Reich
David Littlejohn - Foreign Legions of the Third Reich, vol 4
Kurt Mehner - Die Waffen-SS und Polizei 1939-1945
Rolf Michaelis - Estländare i tysk tjänst 1941-1945: en översikt

Reference material on this unit

August Jurs - Estonian freedomfighters in World War Two
Mart Laar - Eesti Leegion: sönas ja pildis / The Estonian legion in words and pictures
Richard Landwehr - Estonian Vikings
Rolf Michaelis - Esten in der Waffen-SS: Die 20. Waffen-Grenadier-Division der SS (estnische Nr. 1)