On Osmeña Day, September 9, we honor former President Sergio Osmeña Sr., but did you know his real father was only confirmed recently?
More Than Just a Holiday
Every September 9, the country commemorates Osmeña Day, marking the birth of Sergio Osmeña Sr., Cebu’s Grand Old Man and the Philippines’ fourth president. For many, it is simply a non-working holiday. But today’s observance carries a deeper weight. Just last year, in 2023, the mystery surrounding Osmeña’s true parentage was finally resolved through DNA testing, ending more than a century of speculation about who his real father was.
A Century-Old Mystery
Born on September 9, 1878, to Juana Osmeña, Sergio grew up fatherless, the only Philippine president considered illegitimate. Throughout his life, he avoided speaking about his parents, even as he rose from Cebu governor to senator, vice president, and ultimately president during the critical years of World War II. For decades, historians and family members debated two possible fathers, Chinese immigrant and businessman Pedro Singson Gotiaoco or the wealthy landowner Antonio Sanson. No evidence, however, could ever confirm either claim.
Science Brings the Answer
In 2023, descendants of the Osmeña family commissioned professional genealogist Todd Sales Lucero to solve the mystery once and for all using genetic genealogy. DNA samples were collected from former Cebu City mayor Tomas Osmeña, a grandson of Sergio, from a Gotiaoco descendant, and from Ronnie Sanson, a male-line descendant of Antonio Sanson’s family. The results were conclusive, the Gotiaoco line was excluded, while the Sanson line produced a full genetic match. After 145 years, the truth was out, Antonio Sanson was the biological father of Sergio Osmeña Sr.
Legacy Beyond Lineage
The revelation, announced in Cebu last June 2023, stirred both pride and relief among the Osmeña clan. For many, it was the closure that history and family lore had long denied them. Still, as Tomas Osmeña emphasized, Sergio’s greatness was never defined by his father’s name but by his statesmanship, integrity, and service to the Filipino people. From his leadership during the liberation of the Philippines to his role in building Cebu’s political landscape, Osmeña’s true legacy rests on his deeds, not his bloodline.
Osmeña Day Redefined
With this discovery, Osmeña Day in 2025 holds a richer meaning. It is not only about honoring the birth of a national leader but also about embracing the humanity of a man who carried the burden of mystery throughout his life. Today, the holiday stands as a celebration of both legacy and truth, a reminder that history is not fixed in stone but can still be reshaped by science, memory, and the enduring quest for answers.
