From the research findings of Jean-Paul Dumont, an American who studied and wrote about the ethnographic character of some of Lazi’s inhabitants, the town of Lazi was named in honor of the governor-general of the Philippines (February 2, 1854- October 28, 1854) whose full name was Manuel Pavia Y. Lacy. In 1857, it was spelled “Lacy”, until it was changed to “Laci”. Until later it was changed to “Lazi”.
Lazi is home to two grandiose edifices left as legacies by the Augustinians Recollects. These two imposing structures are declared National Historical Landmarks by the National Historical Commission for their antiquity and uniqueness of structures. One of these structures is the San Isidro Labrador Roman Church which was built in 1884. It has preserved its hardwood floor of Ipil-Saligwata, and Molave. The other structure is the San Isidro Labrador Catholic Convent which was built in 1887 and measured 48 by 38 meters. It is the biggest among the oldest convents not only in the Philippines but the whole of Asia.
Lazi became a pueblo or a separate administrative unit on May 31, 1857. In commemoration of this significant event of the history of the place which is the founding of Lazi as a town, One Hundred Fifty-Two (152) years ago, the Sangguniang Bayan of this enacted an Ordinance proclaiming May 31, 2009, as the first celebration of the Charter Day of Lazi, and every 31st of May thereafter as Lazi Charter Day. Thus on May 31, 2010, the Local Government of Lazi commemorated the Lazi Charter Day Anniversary celebration with more significance and meaning.