What is "euphronios"

Euphronios (circa 535 - after 470 BC) was an ancient Greek vase painter and potter, active in Athens in the late 6th and early 5th centuries BC. As part of the so-called " Pioneer Group," ( a modern name given to a group of vase painters who were instrumental in effecting the change from Black-figure pottery to Red figure), Euphronios was one of the most important artists of the red-figure technique. His works place him at the transition from Late Archaic to Early Classical art, and he is one of the first known artists in history to have signed his work.