The Mackenzie–Papineau Battalion was a Canadian military unit that volunteered to fight with the XV International Brigade on the Republican side in the Spanish Civil War.

[1] Unlike the American and British volunteers who included significant numbers of students and intellectuals, the Canadian contingent was almost wholly working class.

In general, the Canadian volunteers were self-educated about the Spanish conflict and its repercussions for Europe if the pro-fascist Nationalist side prevailed.

These factors, together with the comparatively mature age of the soldiers – 61.5% were over thirty – resulted in an ideologically committed Canadian contingent.

[citation needed] From Toronto they traveled to Montreal or, more frequently, to New York City, where they departed by ship across the Atlantic Ocean to France.

[1] In February 1937, the XVth Brigade—composed primarily of English-speaking battalions from the U.S., Britain and Canada—fought in the pivotal Battle of Jarama in which eleven Canadian soldiers were killed.

The Canadians chose this name as a symbol of their national identity and their commitment to the elected Spanish Republican side against the Nationalist insurgency headed by General Francisco Franco.

[7] Company Three of the Mac-Paps (under Lieutenant Lionel Edwards of Edmonton) earned distinction at the Battle of Teruel (December 1937 – February 1938).

[8] After withstanding the most intense artillery barrage of the war, the Canadian soldiers held their battered trench position and routed the advancing Nationalist forces.

The heroism displayed by the Canadians at Teruel won the praise of American and British war correspondents and military observers: "The Battalion received a special citation of bravery from the Army, and Captain E. Cecil Smith was promoted to the rank of Major for his brilliant leadership in the action.

"[8] By early 1938, the tide had turned in favor of the Nationalist side, which enjoyed superior manpower and materiel, due in large part to the aid they were receiving from Nazi Germany and fascist Italy.

The Finnish-American machine gun companies successfully repelled the Nationalists, but the collapse of the front on their flanks compelled the Mac-Paps to join the withdrawal.

The Canadian government continued its policy of ignoring or prosecuting the veterans of Spain, in accordance with the Foreign Enlistment Act.

[10] Because the Canadian government chose non-intervention in the Spanish Civil War, the Mac-Pap volunteers do not have status in military institutions or in the national honoring of veterans.

[13] Dr. Norman Bethune, a key developer of mobile army medical units for the Republican side, is one of the few Canadians to be officially recognized for his service in Spain.

[14] The Canadian folk band, Hudson Valley Sally, recorded a song entitled "The Mackenzie-Papineau Brigade" (note: it should be "Battalion").