The Cavalry Brigade (Ratsuväkiprikaati) existed as a peace-time formation before the war and was brought to war-time strength in June 1941. On 18 June 1941 E/RvPr (HQ of the Cavalry Brigade) was used to form a new HQ for Ryhmä Oinonen (Group Oinonen). As long as Ryhmä Oinonen existed (until April 1942) Ratsuväkiprikaati had a very small HQ consisting only of the commander and a couple of other officers. 
It was deactivated in November 1944.

Commanders

Kenraalimajuri Woldemar Oinonen (9 June 1941 - 18 June 1941)
Eversti Gustaf Ehrnrooth (18 June 1941 - 28 April 1942) (temporary)
Everstiluutnantti Åke Wahren (30 October 1941 - 7 November 1941) (acting)
Everstiluutnantti Hans Olof von Essen (7 November 1941 - 14 November 1941) (acting)
Eversti Lars Melander (28 April 1942 - 17 June 1944) (1)
Eversti Urho Tähtinen (17 June 1944 - 10 September 1944)
Eversti Bertel Ikonen (7 August 1944 - ? August 1944) (deputy)
Eversti Hans Olof von Essen (10 September 1944 - 29 September 1944) (temporary)
Kenraalimajuri Lars Melander (29 September 1944 - 28 November 1944)

Footnotes

1. Melander relieved from command because of brigade's unsuccessful defensive fighting in the face of the Soviet offensive; demanded investigation and cleared of all charges, he later reinstated.

Order of battle

Uusimaa Dragoon Regiment (URR)
Häme Mounted Regiment (HRR)
Jäger Battalion 1 (JP 1)
Jäger Battalion 6 (JP 6)

A memorial to Jääkäripataljoona 6 (Jäger Battalion 6, JP 6) in Lappeenranta (Villmanstrand)
The text on the plaque reads: "Jääkäripataljoona 6 was formed here in 1943. The young jaegers fulfilled their duty without question in the fierce battles on Karelian isthmus, Bay of Vyborg and hills of Ilomantsi. This memorial stone was erected by the battalion veterans on 1983."
.
(Courtesy of MKFI)

Sources used

Research by Mikko H.

Reference material on this unit

P.Kilkki & H.Pohjanpää - Suomen Ratsuväen Historia II.Ratsuväki Suomen Sodissa 1939 - 1944
Eros Jäske - Hämeen Ratsurykmentin Ensimmäinen Eskadroona : Vuoden 1944 Kronikka
Toimikunta - Lapinjääkäripataljoonan (JP1) Historia 1921-1971
A.Juutilainen - Nuoren Jääkärin Tie.Jääkäripataljoona 6 1943 - 1944