[6] Prior to the Insurrection of Jaca, he was detained as a result of his participation in the uprising of Madrid in favor of the Republic and against the dictatorship of Primo de Rivera.

He was released thanks to an amnesty granted by General Dámaso Berenguer, and was later assigned to a Regiment stationed in Santa Cruz de Tenerife, Canary Islands, where he remained until 14 April 1931.

[9] As attaché, and subsequently back in Spain, he helped Portuguese people persecuted by the Estado Novo of António de Oliveira Salazar.

For several years, Romero Giménez was vice-president of the Spanish League for Human Rights, an organization founded in 1922 under the presidency of Miguel de Unamuno,.

Amongst the League's members were Azorin, Dalí, Falla, Azaña, Ortega y Gasset, Miró, Luis Simarro, Américo Castro and García Lorca.

Starting in November 1936, following orders from Colonel Aureliano Álvarez-Coque, Romero commanded a battalion from the Bridge of the French, which was of crucial importance because of its strategic location on the Manzanares River.

[17] Because of disagreements with anarchists, Colonel Romero Giménez requested the dismissal of Ricardo Sanz, a Catalan anarcho-syndicalist, whom he accused of mistreating the soldiers and of bringing prostitutes to the trenches.

As Commander of the 4th Mixed Brigade, and with General Miaja's effective support, he founded and directed a war material factory called "Romero Mechanical Factories", which was dedicated to the production of mortars and ammunition, mines and hand grenades, bombs with aerodynamic design, thermoses, tripods, shields for trenches, spare parts for rifles, machine guns and antitank and antiaircraft guns as well as engine repairs.

It consisted of a large cast iron metal box designed to fragment and produce shrapnel, after the explosion of 15, 35 or 60 kg.

In the aftermath of the Spanish Civil War, Romero Giménez was tried in absentia and sentenced twice to death by Garrote for fighting against the uprising, and for being a Mason.

He, his wife and daughter were saved due to the humanitarian proceedings of Gilberto Bosques,[33][34] Consul of Mexico, distinguished for his outstanding work in helping Spanish refugees, Jews and other people being persecuted, providing them shelter in that country.

He, his wife and daughter arrived to the port of Veracruz on 22 May 1942, after nearly a month's cruise aboard the second of three voyages made from Casablanca by the Portuguese ship Nyassa carrying to Mexico large contingents of refugees.

In this country Romero re-founded the technical magazine Defensa Nacional (National Defense) with the participation of Spanish military refugees in cooperation with the Mexican Armed Forces.

After the death of Francisco Franco in 1975, despite having fulfilled all the formalities, Romero was never granted the state pension as a Spanish military Veteran.

[37][38] On 11 September 1978, Romero peacefully passed away surrounded by his family at age 87 in the Sanatorio Español hospital in Mexico City.

[39] In fulfillment of his will his body was cremated and the ashes divided into two equal parts to be spread to air, water and land, one half in Mexico and the other in Spain.

[citation needed] Spain brutally repressed Masonry, including -as in Romero's case- sentencing members to death by use of medieval torture instruments.