On Aug. 3, 1935, a day so humid you could taste the air, 25,000 Black and White New Yorkers marched down Harlem’s Lenox Avenue to protest fascist Italy’s plans to invade Ethiopia. Ruled by Emperor Haile Selassie, Ethiopia was a League of Nations member and one of two African nations that had never been colonized. The urgency of the cause brought together Black labor, religious and pan-Africanist groups, Italian American leftists and the event’s sponsor, the Communist-linked American League against War and Fascism.

Often relegated to the margins of history, the Italo-Ethiopian War (October 1935-May 1936) brought the world home for America’s Black communities. It awakened many people to sentiments of belonging and allegiance that transcended national boundaries and sparked mass protests. Outside the United States, the war also galvanized many in the Black diaspora to the stakes of anti-racist and anti-fascist struggles. The mass reaction to the invasion of Ethiopia merits attention at a time when a new generation is engaging in sustained protest of racial injustice, and authoritarian aggression is on the rise.

Ethiopia had a special significance for many in the Black diaspora. It was an ancient center of Christianity, and the Ethiopianism religious movement of the late 19th century drew on biblical reference to the country’s special role in fostering African nationalism and independence. Ethiopia also stood as a symbol of anti-imperial defiance and African modernity. In Adwa, in 1896, Ethiopians forced Italian armed forces to retreat, putting an end to Italy’s first attempt to occupy the country. Haile Selassie, then in his fifth year as emperor, also enjoyed global fame. He inspired Rastafari, a cultural and religious movement that considered him as a messianic figure. For millions, the invasion of Ethiopia imperiled Black freedom and dignity everywhere.

For the fascists, occupying Ethiopia was not merely payback for that humiliating defeat 40 years earlier, but a chance to implement dictator Benito Mussolini’s plan to make Italy an agent of white racial rescue. The fascist regime famously persecuted leftists and ethnic and religious minorities, but it also acted to correct perceived threats to the hegemony of white civilization. In 1927, years before Adolf Hitler came to power in Germany, Mussolini warned that white people could face extinction, while “black and yellow people” were “at our doors,” armed with “a consciousness of the future of their race in the world.”

Italy had occupied Somalia, Eritrea and Libya in Africa prior to World War I, but now Ethiopia, slated for population by Italian settlers, would show the world a fascist vision of total racial domination. In the meantime, overwhelming military force, including the deployment of 1,000,000 men and hundreds of tons of illegal poison gas bombs, would ensure victory.

In this climate of emergency, Black and White anti-racists and antifascists came together around the world to organize. In London, Amy Ashwood Garvey led a rally with the Friends of Ethiopia organization. In St. Kitts and elsewhere in the British West Indies, protesters demanded British government action against Italy. In Jamaica, 1,400 men petitioned King George V to be able to enlist in the Ethiopian military. In the United States, Samuel Daniels, head of the Pan-African Reconstruction Association, toured major American cities to recruit volunteers. Soon the State Department reminded community leaders it was illegal for American citizens to fight for a foreign power. Yet two Black pilots, Hubert Julian and John Robinson, found their way to Ethiopia to assist.

New York City became a hub of activities on both sides of the Italo-Ethiopian war. A rally held at Madison Square Garden on Sept. 26, less than a week before the invasion, brought out more than 10,000 to hear civil rights leader W.E.B. Du Bois, Paul Robeson and others speak about the impending disaster.

The rally was also a demonstration of racial unity: Whites, including many anti-fascist Italian Americans, made up three-quarters of the audience that cheered the sight of a 20-foot effigy of Mussolini being destroyed. Blacks and Whites together boycotted Italian businesses, leading to confrontations around the city. Ethiopia built bridges between some New Yorkers — even as it drove others apart.

While some Italian Americans in New York protested Mussolini, others embraced him. These tensions came to a head when the invasion began on Oct. 3 and Italian troops poured into Ethiopia. Italian American and Black students brawled at Brooklyn’s P. S. 178 with lead pipes and ice picks, and a Black protest of Italian vendors at the King Julius General Market on Lenox and 118th Street turned into a riot. The New York City Police Department deployed 1,200 extra policemen on “war duty” to address the unrest. There, as in other American cities, demonstrators also met with police brutality.

Many Italian American communities stepped up their own activism in support of their families’ recent countries of origin — most Italian immigrants had arrived only between 1880 and the 1920s. They recruited combatants and raised funds for the madrepatria by donating wedding rings that would be sent to Italy and melted down for armaments. At a December rally in Madison Square Garden attended by 20,000, Mayor Fiorello La Guardia presented the Italian consul general with a $100,000 check. Admiration for Benito Mussolini fueled much of this support. A celebrity in the United States, Mussolini had had a monthly column in the newspapers owned by his supporter William Randolph Hearst since the late 1920s. A month into the war, as airplanes unleashed tons of poison gas, killing thousands of Ethiopians, a TIME magazine cover depicted Il Duce with his sons, ever the family man.

When Italy declared victory on May 9, 1936, hundreds of African Americans marched once again down Lenox Avenue, smashing the windows of Italian American businesses. In midtown, the American League against War and Fascism picketed the Italian Consulate, with Black and White protesters disrupting an elegant stretch of Fifth Avenue with denunciations of the ongoing slaughter.

Exiled Emperor Haile Selassie made news when he spoke to the League of Nations in June 1936, denouncing “the deadly rain” that killed his people. But the outbreak of the Spanish Civil War one month later, and Hitler’s increasing expansion within Europe, soon made Ethiopia’s plight of marginal concern for most Whites.

Many in the African diaspora knew better. Ethiopia, not Munich, was the first example of appeasement of fascist aggression. As Ethiopian deaths mounted — an estimated 250,000 perished before the Allies drove the Italians out of the country in 1941 — Black people continued to call out Italian oppression from West Africa and the Caribbean. In Lagos, Nigeria, the West African Pilot newspaper published an editorial in March 1938 denouncing the fascists’ use of forced labor.

The Italo-Ethiopian War may remain an obscure historical event to many Americans. Yet it shocked millions into action and fueled a reckoning with institutionalized racism and fascism — propelling many activists, Black and White, to take to the streets of New York and other cities across the world. Much like today, these activists boldly proclaimed that Black lives mattered.

Editor’s note: An earlier version of this piece stated that Italy had occupied Somalia, Eritrea and Libya in Africa since the late 19th century, but Italy occupied Libya in 1911.