Precolonial era Historical records called the town
Ibon, which in the 16th century was a town of
Pampanga.
Spanish colonial era During Spanish rule, in 1595, Gapan was reinstituted as a Catholic town by the Spanish priests Contres Tendilla, Caballo, and Salazar. This makes Gapan the oldest town in Nueva Ecija and one of the oldest in the Philippines. The town had a large jurisdiction embracing an area as far as
Cabanatuan to the north (which was its
barangay with the name Cabanatuan before it separated in 1750); the
Sierra Madre to the east;
San Miguel,
Bulacan to the south; and,
Candaba,
Pampanga to the west. Most of the original settlers in Gapan were Tagalogs from
Bulacan and Morong (now
Rizal Province) and Kapampangans. Other early settlers came from Ilocos and Tayabas (now
Quezon Province). Gapan, along with Aliaga, Cabiao, San Antonio, and San Isidro, was transferred to the province of Nueva Ecija in 1848.
After the Philippine declaration of independence After the 1898 Philippine independence, some of the town's former districts became separate towns until what remained comprised only what are now the towns of
Peñaranda,
General Tinio, and
San Leonardo (formerly called Manikling), all of which are part of Nueva Ecija.
Gapan massacre February 12, 1982 saw one of the prominent
human rights abuses of the Marcos dictatorship in the form of the "Gapan massacre", in which armed soldiers strafed the residence of the Bautista family in the town, resulting in the death of the Bautista couple and all three of their children.
Cityhood By virtue of
Republic Act No. 9022 and its ratification in a plebiscite subsequently held on August 25, 2001, Gapan was converted into a
component city of
Nueva Ecija. Ernesto L. Natividad became the first city mayor of Gapan. ==Languages==