Bert Ahrenberg, whose name also appeared in records as Bertel Arnberg and Bertil Ahrnberg, was born on December 31, 1901, in Malmö, Sweden. He immigrated to the United States in 1921 and eventually settled in Brooklyn, New York. Records place him at 4704 4th Avenue in Sunset Park, a neighborhood that was home to many immigrant and working-class families during the early twentieth century. Ahrenberg worked as a driver, though it is not clear what type of vehicle he operated. Over the next decade, he established himself as part of New York City’s immigrant workforce. Like many working-class New Yorkers, Ahrenberg became increasingly involved in left-wing politics as the economic crisis of the 1930s deepened. In 1933, he joined the Communist Party USA, part of a broader political movement that viewed fascism, unemployment, and the collapse of working-class living standards as pressing social problems.
By 1937, Ahrenberg decided to volunteer for the Spanish Republic and joined the growing number of Americans traveling to Spain to fight against Francisco Franco’s nationalist forces. Although the United States officially remained neutral in the conflict, volunteers continued to leave through networks connected to left-wing political organizations and the Communist Party. Ahrenberg arrived in Spain and entered the International Brigades on June 24, 1937. Rather than serving in a traditional infantry battalion, he was assigned to the Regimiento de Tren, a transport regiment responsible for moving supplies, equipment, and soldiers throughout Republican territory. Given his civilian work as a driver in New York, he was likely assigned to this unit because of his experience operating vehicles and transporting goods. During his service, he achieved the rank of cabo, or corporal, and served on the fronts of Cuesta de la Reina and possibly Tazalejo, though some Republican military records remain difficult to fully reconstruct.
Although Ahrenberg served in Spain for only a few months, conditions for International Brigade volunteers were often extremely difficult. Republican forces struggled with shortages of food, ammunition, fuel, and medical supplies throughout much of the war. As a member of a transport regiment, Ahrenberg likely spent much of his time driving through dangerous areas vulnerable to artillery fire and aerial bombardment while carrying troops or supplies between Republican positions. Unlike many volunteers who served in famous infantry units such as the Abraham Lincoln Battalion itself, transport regiments received far less public attention despite playing an essential role in keeping Republican forces operational. On September 14, 1937, Ahrenberg returned to the United States aboard the SS Veendam. The surviving records do not explain exactly why his service ended after only a few months, though many volunteers left Spain because of illness, injuries, reassignment, political disagreements, or the general exhaustion caused by wartime conditions.
Ahrenberg’s opposition to fascism appears to have continued well beyond the Spanish Civil War. During World War II, he served as a Field Director for the American Red Cross in Port Lyautey in North Africa, Sardinia, Italy, and Germany. Unlike combat soldiers, Red Cross field directors focused on supporting American servicemen by organizing recreational services, distributing supplies, assisting wounded soldiers, and helping maintain morale near active war zones. His wartime assignments placed him across several major theaters of the Allied war effort against Nazi Germany and Fascist Italy. In many ways, this later service reflected the same anti-fascist commitment that had first brought him to Spain in 1937.
After the war, Ahrenberg appears to have remained involved in international work for at least some period of time. A 1951 Foreign Service record likely identifies him as a resident officer in Landshut, Bavaria, working under the American occupation administration in postwar Germany, although it is not certain that this was the same Bert Ahrenberg. Later in life, he worked as a real estate broker and eventually settled in Salt Lake City, Utah. He died there on May 8, 1991.
Much of Ahrenberg’s life remains difficult to fully reconstruct because surviving records are scattered across immigration documents, Communist Party records, military archives, genealogical databases, and Abraham Lincoln Brigade files. Even his surname appeared in multiple forms depending on the source. Still, the surviving evidence presents the outline of a remarkable life that stretched across several of the major political conflicts of the twentieth century. From his immigration to New York in the early 1920s, to his service in Spain with the International Brigades, and later his work with the American Red Cross during World War II, Bert Ahrenberg’s life reflected the experiences of many immigrant anti-fascists who believed the struggles unfolding in Europe demanded direct personal involvement.
Familysearch.org. “FamilySearch.org,” 2019. https://ancestors.familysearch.org/en/LB9G-6TZ/bertil-carl-edvard-arnberg-1901-1991.
Internet Archive. “Foreign Service List : United States. Dept. Of State : Free Download, Borrow, and Streaming : Internet Archive,” 2026. https://archive.org/details/foreignserviceli1951unit/page/n55/mode/2up?q=arnberg.
The Abraham Lincoln Brigade Archives. “Ahrenberg, Bert | the Abraham Lincoln Brigade Archives,” December 9, 2019. https://alba-valb.org/volunteers/bert-ahrenberg/.
Ub.edu. “AHRENBERG, Bert | Sidbrint,” 1936. https://sidbrint.ub.edu/brigadista/ahrenberg-bert.