He was born on September 12, 1924 in Bafatá, Portuguese Guinea, son of a Cape-verdean parents. His half-brother Luís Cabral would later become head of state of Guinea-Bissau. Amílcar Cabral was educated in Lisbon, the capital of Portugal which was the colonial power that ruled over Portuguese Guinea at that time. While an agronomy student at the Instituto Superior de Agronomia in Lisbon, he founded student movements dedicated to African nationalism.
He returned to Africa in the 1950s, and began forming independence movements on the continent. He was instrumental in the formation of the PAIGC or Partido Africano da Independência da Guiné e Cabo Verde (Portuguese for African Party for the Independence of Guinea and Cape Verde). He also worked to form a liberation party in Angola with Agostinho Neto, an associate he met and befriended in Portugal.
Beginning in 1962, Cabral led the PAIGC in a guerrilla movement which evolved into a military conflict against the Portuguese ruling authorities of Portuguese Guinea. The goal of the conflict was to attain independence for both Portuguese Guinea and Cape Verde. Over the course of the conflict, the party won land gains, and Cabral was made the de facto leader of many parcels of land in Guinea-Bissau.
Even before the war for liberation began, Cabral set up training camps in neighboring Ghana with the permission of Kwame Nkrumah. Cabral trained his lieutenants through rigorous mock conversations to talk with their tribal chiefs and convince them to support the PAIGC and the independence movement before he trained them in military tactics. Later in the war, Cabral found that members of the PAIGC who successfully converted their own tribe to the cause of the PAIGC would not leave to help convince and gather the support of other tribes, he instituted a rotation program where his trainees would no longer be sent to their home tribe.
As an agronomist, he realized that his troops needed to be fed and live off the land alongside the larger populace. He taught his troops to teach local crop growers better farming techniques, thus raising the productivity of the farms to feed their own family and tribe, as well as the soldiers in the military wing of the PAIGC. During down time, PAIGC soldiers would till and plow the fields alongside the local population.
Cabral and the PAIGC also set up a trade-and-barter bazaar system that moved around the country and made staple goods available to the countryside at prices lower than that of colonial store owners. During the war, Cabral also set up a roving hospital and triage station to give medical care to wounded PAIGC's soldiers and quality-of-life care to the larger populace, relying on medical supplies garnered from the USSR and Sweden. The bazaars and triage stations were at first stationary until they came under frequent attack from Portuguese forces.
In 1972, Cabral began to form a People's Assembly in preparation for an independent African nation, but disgruntled former rival Inocêncio Kani shot and killed him with the help of Portuguese agents operating within the PAIGC. The Portuguese enjoined the help of this former rival to bring Amílcar Cabral to meet Portuguese authorities to sign a document stating the independence of Guinea-Bissau. The assassination took place on 20 January 1973 in Conakry, Guinea.