Fidel Alejandro Castro Ruz was born on a sugar plantation in Birán, near Mayarí, in the modern-day province of Holguín – then a part of the now-defunct Oriente province. He was the third child born to Ángel Castro y Argiz, a Galician immigrant from the impoverished northwest of Spain who became relatively prosperous through work in the sugar industry and successful investing. His mother, Lina Ruz González, who was a household servant, was also of Galician background. Angel Castro was married to another woman, Maria Luisa Argota, until Fidel was 17, and thus Fidel as a child had to deal both with his illegitimacy and the challenge of being raised in various foster homes away from his father's house.
Castro has two brothers, Ramón and Raúl, and four sisters, Angelita, Juanita, Enma, and Agustina, all of whom were born out of wedlock. He also has two half siblings, Lidia and Pedro Emilio who were raised by Ángel Castro's first wife.
Fidel was not baptized until he was 8, also very uncommon, bringing embarrassment and ridicule from other children. Ángel Castro finally dissolved his first marriage when Fidel was 15 and married Fidel’s mother. Castro was formally recognized by his father when he was 17, when his surname was legally changed to Castro from Ruz, his mother’s name. Although accounts of his education differ, most sources agree that he was an intellectually gifted student, more interested in sports than in academics, and spent many years in private Catholic boarding schools, finishing high school at El Colegio de Belén, a Jesuit school in Havana in 1945. While at Belén, the 21-year-old Castro pitched on the school's baseball team. There are persistent rumors that Castro was scouted for various U.S. baseball teams, but there is no evidence that this ever actually happened.