EDIT: Re-scanned image for better quality
The quality of the scan's not great but this is supposed to be an AU version Alek and Deryn, from Scott Westerfeld's Leviathan series.
It's based off this picture [link]
of Karl Franz Joseph/Charles I of Austria (Alek's cousin) and his wife Zita. I suppose it's a 'what if' picture if Alek hadn't abdicated and they were both older. At this age they'd probably be emperor & empress but I think archduke/duchess fitted this picture better, hence the title.
PS. The thing pinned to Deryn's dress is supposed to be the Air Gallantry Cross.