Probably the foundation of the monastery was made in the 11th century, by the kindred Kaplony, the exact date, however, is unknown. The abbey church, dedicated to St. Martin, was patronized in common by the members of the families descending from the Kaplony kindred: even after the properties were divided among the branches, the monastery was used as common burial place. Among the few written medieval documents on the monastery, the most important is the diploma of 1444, which contains the list of the mobile inventory of the abbey church. The last written medieval source of 1479
mentions the large dimensions of the church and that it has two towers. The monastery was abandoned and became a ruin, during the 16th century. The renovation was initiated by count Alexander Károlyi (1668–1743), descendant of the Kaplony kindred, who donated the monastery to the Franciscans in 1711. The restoration of the monastery probably lasted for a long period, as the first Franciscan monk arrived here only in 1719. During the restoration, the medieval church with two towers, three naves and three semicircular apses suffered significant transformations: some of the medieval windows were enlarged, the main nave was vaulted in 1730. The vaults of the side naves, however, probably kept their original aspect. All the three naves received a common roof at this time.
In addition, a new crypt was built alongside of the southern wall of the church, replacing the old one, situated in front of the sanctuary, in the main nave. The restoration of church was accomplished in 1740. The earth-quake of 1834 seriously affected the church. The restoration of the church and the cloister was made in Romantic style, according to the projects of Miklós Ybl, between 1842 and 1847. The medieval pilasters were demolished (two of the original capitals were recovered, being kept, in the present, in the crypt) and the vaults, except of the three 
sanctuaries, were replaced by a ceiling with cassettes. A new crypt was built behind the sanctuary, with a cross-shaped plan, with the aspect of an early-Christian mausoleum. The coffins of the death members of the Károlyi family were moved to the new location. On the re-consecration of the restored church the initial title of the church, The Nativity given by Alexander Károlyi, was replaced with St. Anthony of Padua. The most valuable elements of the interior are the remnants of the baroque furniture, the oil paintings representing the Stations of the Passion and the bronze sarcophagi in the crypt. (TSz).References:
Tempfli Imre, A kaplonyi monostor-templom, Szatmárnémeti 2002. Otthonom Szatmár Megye 17.