Erminia, Tancredi, Polidoro e Pastore (R.374.26) or more simply Erminia, is the last of the serenades by Italian composer Alessandro Scarlatti. Conceived for four voices, choir and orchestra, the work was created on the occasion of a wedding at the Palazzo Zevallos Stigliano in Naples on June 13, 1723, two years before the musician's death. The second part has gone astray in time and long considered lost or as an unfinished work. In the 2010s, fragments were found thanks to the Répertoire international des sources musicales.