Jose W. Diokno was born in Manila on Feb. 26, 1922, to Ramón Diokno y Marasigan, a former senator and Justice of the Supreme Court, and Leonor Wright, an American mestiza of British descent. Diokno had nine siblings, and some half-siblings from Ramón's first spouse, Martha Fello Diokno, who passed away years ago. Diokno had some Irish, Spanish, Chinese, Mexican or Native American, and very scant South Asian descent. He would later often say that he was "100% Filipino". Ramón Diokno was considered an anti-imperialist nationalist as senator. He opposed the American Parity Rights Amendment and was one of four to be ousted so that the amendment may be ratified. Jose W. Diokno's grandfather was Ananías Diokno, a general in the Philippine Revolution and the Philippine–American War who represented the revolutionary forces in Visayas. Ananías's great-great grandfather was Félix Berenguer de Marquina, the viceroy of New Spain and governor-general of the Philippines from 1788 to 1793, who had an extramarital affair with a Chinese-Filipina mestiza named Demetria Sumulong and sired a daughter. He abandoned his family to return to Spain in 1795 and later became lieutenant-general of the navy in 1799. He was said to be incompetent as governor but persevering.