Chaucer's England provides background for a full-bodied pageant novel centering around the romance of John of Gaunt, Duke of Lancaster, and Chaucer's sister-in-law, convent bred Katherine Swynford. The 14th century swung from magnificence to direst poverty. The Black Death swept social barriers asunder, while court intrigue almost met its match when the peasants won short-lived surcease from woe at the hands of the weakling boy king, Richard II. There's an immense amount of serious research and intimate recreation of time and mood which combine to give this novel a powerful sense of authenticity. And the sweep of history and legend and story make it absorbing reading. Katherine was fifteen when she was summoned to court and wedded- with bitter repinings- to the ill -favored Sir Hugh. Already she had seen and loved John, third son of Edward III, married to the lovely Blanchette, whom he adored. Despite this, he found himself unwillingly drawn to Katherine, and this flowered into illicit passion -- and after Hugh's strange death -- into a long-lived union, paralleling his second marriage of state to the Castillian princess. It is a very human story, and ends with marriage between them after the souls had been cleansed by sorrow and penance. A moving tale, and Miss Seton's most distinguished book- her first with an historical background outside America.