Born in 1884 in Milan, heir of the pharmaceutical company C. Erba. Initiated privately in his studies, in the years around 1900 he developed the decision to devote himself to art in the future.
At the age of twenty he made his first oil painting. Around the same time, at the behest of his father, he enrolled at the University of Genoa at the Faculty of Chemistry, as was the family tradition. The intertwined relationships with the Milanese anarchist circles provoke the intensification of relations with the family, with the consequent abandonment of the Faculty of Chemistry. Between the end of 1906 and the beginning of 1907 Carlo definitively abandoned his university studies and returned to Milan.
In November 1908, Erba enrolled in the courses of the Free Nude School annexed to the Brera Academy. He becomes friends with Carlo Carrà and other artists. Carlo's father, who does not accept his son's decision to abandon his studies to devote himself to painting, refuses him any financial help. In order to live, Erba performs wall decorations and other small jobs.
Between 1912 and 1913 the research of Erba became more committed and intense, and in a decisive transformation of perspectives. In 1914 he was among the founders of the group of New Trends with Giulio Ulisse Arata, Leonardo Dudreville, Achille Funi and Giovanni Possamai, participating in the interventionist demonstrations together with the other futurists.
In the imminence of Italy's entry into the war, Erba joins the futurist friends Marinetti, Boccioni, Funi, Sant'Elia, Russolo, Piatti and Sironi, the critic Mario Buggelli and the journalist Renzo Codara of Corriere della Sera, in the Battalion. Lombardo Volunteers Cyclists Motorists. During the night from 12 to 13 June 1917, during an assault on the white weapon on Ortigara, Carlo Erba fell hit by a sliver of grenade.
The body of Carlo Erba was never found again, despite numerous searches made after the war was over. Erba will receive the bronze medal in memory.