Dabrowski Battalion The Dabrowski Battalion , also known as Dąbrowszczacy ( ) was a battalion of the International Brigades in the Spanish Civil War . It was initially formed entirely of volunteers , " chiefly composed of Polish miners recently living and working in France and Belgium " . Because of the relatively short travelling distances , these men were amongst the first to arrive in Spain . The battalion had a strong Polish flavour and even when , towards the end of the war , Poles were heavily outnumbered by Spanish troops , the officers and non - commissioned officers were still predominantly Polish . It fought from 1936 - 1939 . It fought with great honour and took appalling casualties . The battalion was raised in Albacete ( the headquarters depot of the International Brigades ) in mid - October 1937 . Formation . This battalion was originally part of " XI Brigada Movil " ( " 11th Mobile Brigade " ) which was formed 14 – 17 October 1936 . The volunteers were grouped by language into four battalions to make communication easier . On 22 October 1936 , the IX Brigada Movil was renamed the XI International Brigade ( also known as the " 13th Hans Beimler Brigade " ) , with General " Kléber " ( Manfred Stern ) commanding . The four component battalions were renamed as follows : Soldiers . About 5 , 000 Poles fought in that unit . The Brigade was named after the 19th century Polish general Jarosław Dąbrowski . The unit was formed as " Dąbrowski ' s battalion " in October 1936 ; in June 1937 it was reorganised into the " 150th Brigade " , which in addition to two Polish battalions ( " Dąbrowski ' s " and " Palefox ' s " ) included also a Hungarian ( " Rakosy ' s " ) and a Belgian - French ( " Marty ' s " ) one . In August it was renamed again to the " 13th Dąbrowski ' s International Brigade " . The brigade was demobilized in 1938 but volunteered back to service in 1939 . On 9 January it crossed the French border and was finally dissolved ; most of its soldiers were interned . Most of Dąbrowszczacy were Polish communists . For their communist orientation they were condemned by the Second Polish Republic , which cancelled the citizenship of many of them ( in spite of the fact , that Poland was second biggest arms supplier to the Republic , just after USSR ) . On the other hand , they were portrayed as heroes in the People ' s Republic of Poland ; many of them served in the Berling Army , Armia Ludowa and Gwardia Ludowa during the Second World War . Siege of Madrid . By early November , the Siege of Madrid was underway and the need for men was great . The 600 - man strong Dabrowski Battalion , along with the rest of XI International Brigade were the first units of the International Brigades to go into action . The Dabrowski Battalion was in the thick of the action - at University City and Casa de Campo - losing two thirds of its men . It was subsequently reinforced by new volunteers arriving from Albacete and by Spanish volunteers , and regorganised into three Polish / Balkan companies and one Spanish company . Battle of Jarama . The Dabrowski Battalion , as part of the XII brigade , was sent to Jarama , a few kilometres from Madrid , to block a Nationalist attack . The Nationalist aim was to take the main Madrid to Valencia highway and thus cut Madrid off from Andalusia , where the Republican government was based . The fighting was ferocious with all five International Brigades engaged along a continuous front . At Jarama , the battalion was commanded by Józef Strzelczyk . During the course of the battle , the Battalion lost a third of their effectives . ( 6 – 27 February 1937 ) Order of battle . The Dabrowski Battalion served in several brigades . As its numbers were reduced by casualties , it absorbed various other reduced international battalions , supplemented by Spanish conscript companies , but it never again reached full strength . It was demobilised in September 1938 .