Antolín was born in Salamanca, Castile and León on October 9, 1918. He is married, and has a son named José Antonio de Santiago-Juárez, who is also a politician. He graduated from the University of Valladolid. He celebrated his 100th birthday in 2018. He joined the university as a professor for some time. He was advocated in the court of Valladolid and was engaged in the profession of journalism.
