The present town is a recent development, established by Royal Decree in 1928 by the merger of Mortaso, Borzago and Fisto into a single municipality called “Spiazzo”, a place name referring to the centre of the three communities.
Its origins can be traced back to a Sanctuary dedicated to St Vigilius. It is in fact the place where the bishop of Trent is said to have been martyred on 26 June 405, during his last missionary journey. Tradition has it that where the high altar of St Vigilius' church now stands, a stele to the god Saturn once stood. The bishop is said to have torn it down, provoking a tragically murderous reaction from the pagan population. The place was thenceforth converted to Christian worship, however, and the town is considered the historic seat of the Pieve di Rendena.
