The brigade was officially created on July 29, 1936, while militarizing the Fifth Regiment's militias and those organized in the provinces of Toledo, Cuenca and Guadalajara, being assigned to the latter.

Some 800 militiamen of the UGT of Cuenca, Guadalajara and Albacete were also integrated into the brigade (in its 3rd Battalion), placing commanding officers at their command.1 The first commander of the unit was the largest of the captain Ventura Monge, then the war it reaches the jarama was Joaquín Pérez Martín-Parapar; the chief of staff, the militia officer Sánchez; and the political commissar, Ernesto Antuña García.

Intervened in the Battle of Jarama attacking the hill of El Pingarrón on February 19, after winning and losing three times, the unit is decimated and in the front line, then being eliminated a company commanded by Captain Ventura Monge that could only resist in the trenches waiting for a support that will never come, The freedom days after will echo its disappearance.

The combat around the municipalities of Abánades and Sotodosos cost the brigade many losses, The commander of the 261st Battalion, the eldest of militias Juan Molina Aliaga, was discharged for dissensions with his commissar.

The commander Vivó was replaced by the eldest of militias José del Rey Hernández and took over as commissioner Francisco Testiliano.

On August 2 of that year he entered the front line of combat, trying to oppose the Francoist offensive on Cabeza del Buey (Badajoz), without success.