Giovanni Martini was born in Udine in the 1470s and died in the city in 1535, having painted mostly religious images throughout his career. This image of Saint John the Baptist was painted in the early 1490s and I hadn’t realised that the Ecce Agnus Dei on this painting means “Behold the Lamb of God”, the words used by John Baptist before baptising Jesus. It’s one of the more sympathetic portrayals of John the Baptist that I’ve seen, quite an elegant artwork.
Martini spent most of his time in Friuli, north of Venice, so I’m not sure if he ever visited Florence. The National Gallery in London have another of Martini’s works, which is a panel painting which would have been used as an altarpiece. It was in such poor repair that the gallery didn’t show it, but recently a significant project was undertaken to restore it and bring it back on display, with details at https://www.nationalgallery.org.uk/whats-on/complex-conservation-an-altarpiece-in-need-of-attention.