Date unknown. Saint Ust has been described as a hermit or a
martyr or even a bishop, but nothing is known with certainty. His
various stories may have been an amalgam of those of several holy
men. Nevertheless, he is the patron of the church of Saint Just
near Penzance
(
Benedictines).
Church of Saint Just-in-Roseland
http://homepages.tesco.net/~k.wasley/justrose.htm