4 Unpeopled, unmanured, unproved, unpraised,
unmanured > unploughed, uncultivated
5 Nor was it island then, nor was it peised
peised > balanced; weighed down; weighed upon
6 Amid the ocean waves, nor was it sought 7 Of merchants far, for profits therein praised,
Of > By praised > valued, esteemed
8 But all was desolate, and of some thought
of > by some > [some of the chroniclers whom Spenser consulted]
9 By sea to have been from the Celtic mainland brought.
Celtic mainland > (Normandy and Brittany)