ɐ nˈeɪɾɪv ʌv ɪmjˈuːz, kˈævaɪt, sˌæntɪˈɑːɡoʊ wʌzðɪ ˈoʊnli tʃˈaɪld ʌv ɹˌɛvəlˈuːʃənˌɛɹi dʒˈɛnɚɹəl mˌæɹiˈɑːnoʊ ˈælvɚɹˌɛz wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd ˈeɪtiːn nˈaɪntiːnhˈʌndɹɪd twˈɛnti fˈoːɹ ænd nˌɪkəlˈɑːsə vɜːɹˈɑːɾə.
A native of Imus, Cavite, Santiago was the only child of revolutionary general Mariano Alvarez (1818–1924) and Nicolasa Virata.