From the prologue of Francesca Caccini's La Liberazione di Ruggiero:
Meco venite, e con sonore voci, / Numi dell'acque, reverite in pace, / Chi vinse in guerra il Moscovita e'l Trace, / E servirese i Tartari feroci.
Is "servirese" an archaic conjugation of "servire"? (Passato remoto forse?) It doesn't make grammatical sense as an infinitive + reflexive pronoun, and furthermore it is set musically so that the 3rd syllable is stressed.