[Two boys on a roof top pointing at smoke rising in the distance of the city, Madrid, Spain]

[Republicans at the last line of fire before the summit, Rio Segre, Aragón front, near Fraga, Spain]

[Republican soldiers on a staircase during the battle for this strategically located hilltop town, Teruel, Aragón front, Spain]

[Republican soldiers in trenches during the battle for this strategically located hilltop town, Teruel, Aragón front, Spain]

[People watching planes, Barcelona]

[Watching an air battle over Barcelona]

[Dolores Ibárruri Gómez, La Pasionaria, and Jose Diaz at the farewell parade for the International Brigades, Barcelona, Spain]

[Republican soldier reading a map with a comrade while talking on the phone, Rio Segre, Aragón Front, near Fraga, Spain]