San Pedro de Ansemil is a small and ancient monastery, originally mixed and of a family nature. Its foundation could be placed between the 9th and 10th centuries, and some have even suggested the specific date of the year 919, during the time of Bishop Sisnando I of Iria, although there is no documentary evidence to confirm this. The first written reference dates back to the year 972, when Lady Fredeande made a donation in its favor. Other documents record subsequent donations, dated 1111 and 1192.
By the year 1083, the two communities had split, and the nuns had possibly moved elsewhere. At this time, the monastery is explicitly documented as belonging to the Benedictine order. Later, it seems to have fallen into decline and eventually disappeared, as there is a documentary gap until the year 1262. From this date onwards, the monastery was occupied exclusively by nuns. In the 14th century, a funerary chapel was founded next to the monastic church, sponsored by Diego Gómez de Deza († 1341), one of the monastery's main patrons. However, by the late 15th century, the monastery was in a state of decline and without a community. The last abbess was Isabel de Ulloa, who was also abbess of San Pedro de Vilanova. In 1499, both monasteries, already inactive, were annexed to San Paio de Antealtares.
Of the original monastery, only the church has been preserved a structure with three naves and three rectangular-plan apses, reflecting the influence of an earlier building. Attached to the church is the Deza Chapel, also known as the Chapel of Santa Ana, along with a bell tower that was added at the beginning of the 20th century. No other monastic buildings remain, but traces of pre-Romanesque architectural elements have been found.
- FREIRE CAMANIEL, José (1998). El monacato gallego en la alta edad media, vol. II. La Corunya: Fund. Pedro Barrié de la Maza
- GARCÍA GUINEA, Miguel Ángel; dir. (2012). Enciclopedia del románico en Galicia. Pontevedra. Aguilar de Campoo: Fundación Santa María la Real
- MOURE PENA, Teresa C. (2004). Revisión histórico-documental en torno al antiguo monasterio benedictino de san Pedro de Ansemil. Descubrindo, núm. 6
- PÉREZ RODRÍGUEZ, Francisco Javier (2008). Mosteiros de Galicia na Idade Media. Ourense: Deputación Provincial de Ourense
- ZARAGOZA PASCUAL, Ernesto (2002). Reforma de los monasterios de Lobás, Dozón y Ansemil (1498-99). Cuadernos De Estudios Gallegos, num. 49
Ansemil belongs to the municipality of Silleda (Pontevedra), located southeast of Santiago de Compostela, in the direction of Ourense