What drew Yourcenar to the topic of the emperor Hadrian?

Have to say that Margeurite Yourcenar's Memoirs of Hadrian (1951) is growing on me. Even though I know little about Hardian and had not thought I'd be particularly interested in a Roman czar from when, the first century?, somehow MY is catching and holding my interest. It's a little tough going at first - there are so many names, various Roman figures including politicians, soldiers, artists, others, and so many place names, and believe me unless your a scholar of the Classics most will be unfamiliar to you, but ultimately you have to say, it doesn't really matter, it's as if you're reading a recently uncovered manuscript about a distant time and the references, familiar and topical at the time of composition, are obscure to us and meant to be so. Getting through that barrier, the novel moves along well and fairly swiftly; it's not about character developing (except for Hadrian's) and not about detailed accounts of war or senatorial debates. The many incidents are all dealt with summarily, as if the readers - or, the reader, as the conceit is that Hadrian is composing this memoir to aid his successor, Marcus Aurelius, would be familiar w/ the details. But the overall picture is important: MY portrays Hadrian as the first Roman emperor to seek peace and resolution. His predecessor and benefactor, Trajan, lived and served to expand the Roman empire, a venture that Hadrian realizes, during his service in the army, was reckless and unsustainable. (You can still see Trajan's column in Rome, on which are engraved many scenes from his significant battles; the novel includes several images from the column). Hadrian comes across as the first modern democratic leader; his goal is to pull back the scope of the empire, to make peace w/ the surrounding states - he realizes that otherwise Rome will be in constant battle and will be drained of all its resources (he's mindful of Alexander's demise through over-reaching). Pursuing this course, he develops enemies; he tries to reconcile, but fails, and one of his loyal supporters assassinates H's 4 key enemies. Hadrian laments that he has to be cruel to the supporter who went outside the law and he exiles the man - but notes in the memoir that the exile was for short term only & both understood that. So H can be a pragmatist and brutal realist (as long as others do the dirty work) as well. One open question still is what drew MY to this material? I have to think that in 1951 she (a French author) was still thinking about WWII and maybe her attachment to Hadrian has something to do w/ the growth and corruption of empire and the need to international accord?