Antonio Hilario, popularly known as Tonyhil or Hilton in the pre-martial law student movement, grew up in Quezon City's La Loma district. His father was a lawyer and his mother a school nurse.
Among their ancestors, the family was proud to count Tiburcio Hilario, the first revolutionary governor of Pampanga under the First Philippine Republic, and Marcelo Hilario del Pilar, one of the 1896 Revolution’s most well-known figures. Zoilo Hilario, a noted poet in Kapampangan and Spanish who later became a congressman and a trial judge, was his grandfather.
The fourth of seven children, Tonyhil had a quiet childhood. He made toys out of scrap wood and later showed an interest in electronics, taking apart broken-down transistor radios to see how they worked. He rarely socialized, preferring to read or go to the movies instead of playing basketball.
After graduating from high school, he enrolled in electrical engineering at the University of the Philippines. However, he never completed his course, as campus political activities began taking up all his time.
In those early years of student activism, Hilario emerged as a leading figure. He led discussion groups organized by the UP Nationalist Corps, and participated in its many countryside trips as part of the group's learning-from-the-masses program. It was here where Tonyhil first learned about rural poverty and oppression.
He was at the historic rally of 26 January 1970, which opened the turbulent period called the First Quarter Storm. He ended up that night nursing a bandaged head and a body turned black and blue by police truncheons. The experience seemed to strengthen his convictions.
Hilario was among the founding members of the Samahang Demokratiko ng Kabataan (SDK), a militant youth group that quickly moved into the forefront of the student movement. As its first secretary-general, he took charge of building SDK chapters in Quezon City, in Manila's university belt and poor communities and in other urban centers outside of Metro Manila. Under his leadership, SDK membership grew from a few hundreds to thousands nationwide.
When President Marcos suspended the writ of habeas corpus in 1971, Hilario was included in a list of activists charged with subversion. Then the following year, when martial law was imposed, SDK went underground and so did he.
His initial assignment in the revolutionary underground was to build clandestine youth groups in Manila that would support the resistance to martial law. Later, he was sent to Panay island to organize rural communities, train armed recruits, and expand guerrilla operations there.
Less than two years after, he was killed while meeting with several other people inside a hut in a remote village of Libacao, Aklan, in the mountain fastnesses of central Panay. Without warning, government troops had surrounded them and opened fire. Antonio Tagamolila and Rolando Luarca were killed instantly, along with the pregnant villager who owned the hut. Hilario, hit in the chest, urged his other companions to leave quickly. A witness said that the soldiers beat him up and had him dig a grave for himself and his two dead comrades. The bodies were exhumed later, and the family gave Tonyhil a proper burial in a Manila cemetery.
Much admired for his quiet strength and simple, hardworking ways, Antonio Hilario lies in his grave with an epitaph that reads: "Behind the words, 'contradiction', 'dialectics', 'struggle' lies the desire to see man become human again."