Julio Arostegui mentions a sole Carlist cavalry unit called "Escuadron de Borgona" organised in Malaga during February 1937. This seems to be the only Carlist cavalry unit which survived the war.

The unit is referred by R. Casas de la Vega ("las Milicias Nacionales" vol II) as the "Third F.E.T. Burgundy Squadron". Now, get a map of South Spain. Ready?

Organised by Malaga's Requetes (9 - 10 officers and around 160 cavalrymen), after a training period it is sent by train to the Cordoba front. From May 37 to March 38 this unit has a patrol and recon role in the Canete de las Torres area and Porcuna.

In March 1938 at the Valenzuela sector, the unit supports the attack to Vertice Atalaya (Peak), and remains in a defensive position up to April. In June, the unit rode to Cordoba and Penarroya, with different roles at Membrillar sierra. On June 15th they charge and support the breach of enemy lines at Cerro de Mariscal (Peak) near Blazquez (Cordoba). The unit helps the advance on Trapera, Mesegara and Torozos sierras, occupying the Penarroya area.

In July, it is organised within the Cavalry division, and through a bridgehead at Mesegara sierra, it advances up to Mataborrachas cortijo. Following the Serena offensive the squadron conquers Puerto Urraco (mountain peak) and Benquerencia village on the 22nd. The unit supports the conquest of Castuera (Badajoz). During the second fortnight of August a Republican attack is stopped by the unit at Mataborrachas cortijo.

At the end of 1938, they are once again in the cavalry role in Badajoz province. IN January 1939 the unit attacks Sierra Carbonera and Sierra Quemada at Penarroya sector, also Sierra de Acebuche and Sierra Madrono near Granja de Torrehermosa, and finally at Sierra de Grana near Fuenteovejuna. The unit finishes the war in its role as a reconnaissance unit in the Belmez area.

Rafael Casas also mentions three other Carlist cavalry units, although none of them remain on duty at the end of the war.

The first one (First Burgundy squadron ?) is a small unit created in Malaga province before the Republican fall of Malaga city, with 82 cavalrymen, which are sent by their own request to the Central front in November 1936. It deployed at Tajo river sector, and had recon duties (Albarreal del Tajo and Burujon). Before the unification decree, it was under the command of a 'Requete' named Halcon Imelewski. After the decree the cavalry captain Carlos Mencos Lopez took command of the unit and it was sent to Southern Spain.

A second unit is found in October 1936 in Badajoz province. Its headquarters are at Guarena and it is just a "Section" size unit.

A third one is a late war ' Requete' unit appearing at Teruel. Section sized and under the command of the cavalry "provisional" Alferez Boris Yllin Borck (probably a "white" Russian. This is not the only Slavian name among Carlist officers, and J. Nagore mentions a Lt. Goguidjonshvili in the 'Tercio de Navarra'). The unit was used for reconnaissance duties at Alto Tajo, and in support roles within the Tercio de Requetes 'Dona Maria de Molina y Marco de Bello.

Sources

R. Casa de la Vega (Las MiliciasNacionales).
Julio Arostegui(Combatientes Carlistas en la guerra civil 1936-1939)
J.M. Bueno (Uniformes Militares de la guerra civil Espanola).

Related

Carlist Military Organization (Abanderado v3n4)