Final offensive of the Spanish Civil War The final offensive of the Spanish Civil War took place between 26 March and 1 April 1939 , towards the end of the Spanish Civil War . On 5 March 1939 , the Republican Army led by Colonel Segismundo Casado and the politician Julián Besteiro rose against the Socialist prime minister Juan Negrín and formed a military junta , the Council of National Defense ( " Consejo Nacional de Defensa " or " CND " ) in order to negotiate a peace deal . Negrín fled to France , but the Communist troops around Madrid rose against the junta , starting a civil war within the civil war . Casado defeated them , and started peace negotiations with the Nationalists , but Francisco Franco only accepted an unconditional surrender . On 26 March the Nationalists started a general offensive and by 31 March they controlled all Spanish territory . Hundreds of thousands of Republicans were arrested and interned in concentration camp s . Background . Fall of Catalonia . After the fall of Catalonia in February 1939 , the military situation of the Republic was hopeless . The Republic still had the capital city and 30 per cent of Spanish territory , but it had lost 220 , 000 soldiers , the second city of the country , and the industrial resources of Catalonia . Furthermore , on 27 February Manuel Azaña , the president of the Republic , resigned and the United Kingdom and France recognized the Nationalist government . Military situation . The Republican army still had between 250 , 000 and 500 , 000 men , but only had 40 aircraft ( three " Natasha " and two " Katiuska " bomber squadrons , and 25 " Chatos " and Moscas fighters ) , little artillery and few automatic weapons . Many soldiers were unarmed ( in December 1938 the Republican army had only 225 , 000 rifles ) , and lacked shoes and overcoats . In Madrid , there was only food for two months , and no water , heating , medicine or surgical dressings . On the other hand , the Nationalist army had more than a million men at the end of 1938 ; among them 35 , 000 Moroccans , 32 , 000 Italians and 5 , 000 Germans , plus 600 aircraft . Opposition to continued resistance . On 16 February , the high command of the Republican army told the prime minister , Juan Negrín , that further military resistance was impossible . Most of the members of the Republican Army , the PSOE , the UGT and the CNT , believed that it was necessary to initiate peace negotiations . Nevertheless , Negrín , backed by the Communist PCE , wanted to continue fighting , because Franco rejected giving any guarantee against reprisals and he believed that a continental war against fascism was imminent . Furthermore , he wanted to organize the evacuation of those most at risk . Casado ’ s " coup " . The plot . From the end of February 1939 , Colonel Segismundo Casado had been preparing a " coup " against the Negrín government in order to start peace negotiations with the Nationalists , believing that the government was too subordinate to the Communists . Colonel José Cendaño , a Fifth column agent inside the Republican army , promised to him that Franco would guarantee the lives of the Republican officers who had committed no crimes . Most of the non - communist elements of the Popular Front in Madrid supported the plot , among them one of the leaders of the PSOE , Julián Besteiro , because they believed that continuing the war was useless . Furthermore , after the surrender of Minorca , many Republican officers in the central zone believed that they could negotiate a deal with the Nationalists . On 2 March , Negrín announced a number of new appointments in the Central Zone . Colonel Casado and the Communists Juan Modesto and Antonio Cordón García became Generals , General Manuel Matallana was appointed as head of the central general staff and communist officers were appointed to command the ports of Murcia ( Manuel Tagüeña ) , Alicante ( Etelvino Vega ) and Cartagena ( Francisco Galán ) . ( According to Beevor , Francisco Galan was appointed military governor of Cartagena ; Etelvino Vega governor of Alicante ; Leocadio Mendiola commander of Murcia ; and Inocencio Curto commander of Albacete ) . The non - communist elements believed that the communists wanted to control the evacuation harbors and joined the plot against Negrín . The " coup " . On 5 March 1939 , Colonel Segismundo Casado , supported by General Matallana , the CNT ( Cipriano Mera ) , the secret service of the Republic ( the Military Investigation Service , " Servicio de Investigación Militar " or " SIM " ) , a section of the PSOE ( Julian Besteiro ) and a section of the UGT ( Wenceslao Carrillo ) , deposed Negrín and formed a military junta , the National Council of Defense ( " Consejo Nacional de Defensa " ) in order to negotiate a peace deal with Franco . On 6 March , Miaja joined the rebellion and was appointed president of the junta . The other members of the junta were Casado , Julian Besteiro , Wenceslao Carrillo , Gonzalez Marín and Eduardo Val ( CNT ) , Antonio Perez ( UGT ) , and the republicans Miguel San Andrés and Jose del Río . Colonel Adolfo Prada was appointed commander of the Army of the Centre , the communist commanders of the I , II and III Army Corps of the Army of the Centre were relieved , the PCE ' s newspaper " Mundo Obrero " was closed and Casado ordered massive arrests of communist commissars and militants . Ironically , Casado ' s justification for the coup was that Negrín and the PCE wanted to carry out a Communist takeover – an identical justification to the Nationalist uprising that began the Civil War – but in fact , he rose against the government because he wanted to negotiate peace and believed that removing Negrín and the Communists was a precondition to negotiations with Franco . In addition to other assurances , the British government said to him that Franco would guarantee the lives of the Republicans . Casado had said to the commander of the Republican Air Force , Hidalgo de Cisneros : “ I give you my word . . . that I can better terms from Franco than Negrín ever can . I can even assure you that they will respect our ranks . ” . After a failed attempt to negotiate with Casado , on 6 March Negrín fled to France from the Monovar ' s airfield , near Elda , with Hidalgo de Cisneros , the leaders of the PCE ( La Pasionaria and Vicente Uribe ) , and the foreign minister Julio Álvarez del Vayo , in order to avoid capture by the supporters of Casado ( Casado wanted to arrest the government and the PCE ' s leaders in order to hand them over to the Nationalists ) . The fight in Madrid . Casado ' s " coup " was supported by the commanders of the other three Armies of the Republican army ( Leopoldo Menéndez López , commander of the Levante Army ; Antonio Escobar , commander of the Estremadura Army ; and Domingo Moriones , commander of the Andalusia Army ) . Nevertheless , the army units settled around Madrid and controlled by the PCE ( the I corps of the Army of the Centre led by Luis Barceló and the Emilio Bueno ’ s II and Antonio Ortega ’ s III Corps ) , rose against the junta on 7 March , starting a brief civil war inside the Republic . Barceló appointed himself as commander of the Army of the Centre and his troops closed all the entrances to Madrid , occupied most of the city center and detained and shot three of Casado ' s colonels . The supporters of Casado only held some government buildings and the south - east part of the city . Nevertheless , Mera´s IV corps counterattacked and occupied Torrejon and Alcala de Henares as the Nationalists started an offensive towards the Manzanares . By 10 March , Barcelo ' s troops had been surrounded and ceasefire was arranged . On 11 March , after days of bloody combat , Casado , backed by the IV corps of Cipriano Mera , defeated Barceló ’ s troops . Barceló and his commissar José Conesa were arrested and executed . There were hundreds of dead ( Thomas : 230 , Jackson : 1 , 000 and Beevor : 2 , 000 dead ) . Cartagena . There was also combat in Ciudad Real and Cartagena . In Ciudad Real Escobar ' s Extremadura Army crushed the communist resistance led by the deputy Martínez Cárton . Nevertheless , in Cartagena ( the main base of the Spanish Republican Navy ) , where the supporters of Casado , backed by elements of the Fifth column , had started the uprising against Negrín ' s government on 4 March , they were defeated by the PCE ' s 206th Brigade , of the IV Division , led by colonel Joaquin Rodriguez , after a brief combat , on 7 March . Nevertheless , on 5 March , the Republican Navy ( three cruisers and eight destroyers ) led by Admiral Buiza , had fled to Bizerte after a Nationalist air bombing . One Nationalist transport ship , the " Castillo de Olite " , sent by the Nationalists in order to support the uprising , was sunk by the coastal batteries of Cartagena , killing 1 , 200 Nationalist soldiers . Peace negotiations with Franco . After the defeat of Barceló ' s troops , the Council tried to start peace negotiations with Franco , hoping to achieve a guarantee against political reprisals . On 12 March the Council proposed a peace deal , asking for a guarantee against reprisals and a period of 25 days to allow anyone who wanted to leave Spain to do so . On 16 March , Franco answered that he would only accept an unconditional surrender . On 23 March , the Council sent two negotiators to Burgos ( Colonel Antonio Garijo and Major Leopoldo Ortega ) , and the Nationalists told them that on 25 March the Republican Air Force had to be surrendered and by the 27th the Republican troops had to raise the white flag . Nevertheless , on 25 March , the Republicans did not surrender their Air Force due to bad weather and Franco broke off negotiations with the junta . The final offensive . On 26 March , Yague ’ s troops advanced in Sierra Morena . There was no resistance and in one day they captured two thousand square kilometers of land and 30 , 000 prisoners . The Junta ordered its soldiers not to resist the Nationalist advance and the Republican soldiers threw away their weapons and abandoned the front . By 27 March , the Nationalists were advancing on all fronts without resistance . Solchaga ' s Navarra Corps , Gambara ' s CTV and Garcia Valiño ' s Army of Maestrazgo advanced from Toledo . On 28 March , Colonel Prada , commander of the Army of the Centre , surrendered to the Nationalists and Nationalist troops occupied Madrid . Casado and the other members of the junta , except Besteiro , fled to Valencia . On 29 March , the Nationalists occupied Jaén , Ciudad Real , Cuenca , Albacete and Sagunto . 50 , 000 Republican refugees gathered at the harbours of Valencia , Alicante , Cartagena and Gandia , but without the Republican navy , an evacuation was impossible and the French and British governments refused to organise an evacuation . Only a minority , those who had money to pay for passage , were evacuated by British ships ( between 650 and more than 3 , 500 ) , among them Casado . On 30 March , the Nationalists occupied Valencia and Gambara ’ s troops entered Alicante , rounding up 15 , 000 Republican refugees . The Italian General Gambara was prepared to permit the evacuation of political refugees , but on 31 March , the Nationalist troops arrived and took over jurisdiction from Gambara . As a result , many refugees committed suicide in order to avoid capture by the Nationalists . On 31 March , the Nationalists occupied Almeria , Murcia and Cartagena , controlling all Spanish territory . By 1 April 1939 the war was effectively over . Aftermath . On April 1 , the United States recognised the Nationalist government , leaving the Soviet Union as the only major power that did not recognise it . The new regime had signed a Non - Aggression Pact with Portugal and a treaty of friendship with Nazi Germany on March 31 , and on April 6 , Franco made public Spain ' s adherence to the Anti - Comintern Pact . On April 20 , the Non - Intervention Committee was dissolved and by June Italian and German troops had left Spain . The Francoist dictatorship remained until Franco ' s death in 1975 . Casado remained in exile in Venezuela until returning to Spain in 1961 . Cipriano Mera fled to Oran and Casablanca , but he was extradited to Spain in February 1942 . In 1943 , he was condemned to death , a sentence that was exchanged for 30 years in prison , but he was set free in 1946 and fled to France . Miaja fled to France and then Mexico , where he died in 1958 . Matallana was detained and imprisoned by the Nationalists and died in Madrid in 1956 . Besterio was arrested by the Nationalists , where he faced a court martial and was sentenced to 30 years in prison . He died in prison in 1940 . The Nationalists arrested hundreds of thousands of Republican soldiers and civilians , with 150 , 000 soldiers captured in the final offensive , and herded them into improvised concentration camps . There were between 367 , 000 and 500 , 000 prisoners in 1939 . In the first years after the war , 50 , 000 Republican prisoners were executed . In literature . Casado ' s coup and the last days of the war are the background of the Max Aub ' s novels , " Campo del Moro " and " Campo de los Almendros " .