Everything indicates that the name «Ribeira» of this parish of Loivos da Ribeira, is linked to that of D. Martim Pais «de Ribeira», brother of D. Maria Pais de Ribeira «a Ribeirinha», family with many assets in Ribeira de Pena, for it was land where his ancestors dominated.

This parish of Tresouras, whose patron is S. Miguel, is quite old, comprising 483 ha, which corresponds to 3.31% of the total area of the municipality.