Ultima Thule was published in 1917 and it is the third novel in the 1930s trilogy The Fortunes of Richard Mahony by Henry Handel Richardson. It won the Australian Literature Society Gold Medal for 1929 and this is the scholarly edition. The trilogy reflects the foundational years of Victoria through the restless, eventually harrowing narrative of the Mahony family, and centrally through the life of Richard Mahony, voyager, questor, idealist. The cuts that the author made for the 1930 single-volume omnibus edition have all been restored from the author's preferred version. This unique edition includes notes and source material.

"...in these three volumes we have one of the greatest novels not only of our generation but of our language...I see Henry Handel Richardson as another Balzac, with all the Frenchman's passion for completeness in breadth and depth and height." - Arnold Palmer, Sphere, 1929