[2] In 715 however, the diocese was suppressed (possibly with an apostolic succession of errant bishops), due to the Moorish invasion of Iberia, rendering the church's cathedral function void.

[2] Thirty years later (1197) the region was donated to Lopo Fernandes, then Templar Master in Portugal, who two years later saw the transference of the 'revived' episcopal seat to Guarda, diminishing Idanha's importance,[2] when the bishopric was nominally 'restored' in 1199 but renamed after its new see as Diocese of Guarda, which built its own cathedral and abandoned the Egitânia title, without awarding Co-cathedral status (like the former Cathedral of Pinhel, another former bishopric).

[2] In 1326, the Templar Knights received 500 pounds from the Commander of Rio Frio, for the "spiritual" benefit and temporal needs of the local population.

[2] But by the 16th century, the church was found partially buried, and work was initiated to recuperate the site, resulting in the correction of the orientation of presbytery.

[2] Over the principal portico was a stone belfry with two bells and decorated with a weather vane, while to the left of the awning was a building with five arches.

[2] On 10 October 1537, Father António Lisboa visited the site and noted that there was an exterior doorway with awning, supported by five columns, 6 varas high.

[2] The chapel had 4 varas length and 4 wide, covered in azulejo tile, that included an old retable with a painting of the Virgin Mary, surmounted by red twill canopy.

[2] The site was ceded to the IPPAR Instituto Português do Património Arquitectónico (Portuguese Institute of Architectural Patrimony) on 12 February 1998.

The cathedral lies in a fortified settlement situated on the right margin of the River Ponsul,[3] implanted in the lowlands south of Monsanto.

The principal facade is oriented to the northeast, two stories tall with an arched doorway with rectangular lintel, secondary circular oculus and belfry.

The southeast lateral chapel is rectangular and covered in vaulted ceiling, with a mural painting that represents St. Bartholomew with the devil at his feet (in ochres and burnt sienna) and decorative flourishes (in grey).