"...the author claims [it] is historically accurate, apart from the romance story within it.
The story occurs just a few months after "The Street of the First Shell" in The King In Yellow. After the defeat of the Franco-Prussian War there was a communist insurrection in Paris and a short-lived Reign of Terror in the spring of 1871. The story is exciting (if perhaps a bit too long) and has plenty of fighting, escaping, jumping over walls and wearing disguises; in this sense it is a adventure-romance in the mode of The Prisoner of Zenda, although quite a bit more scary in that the background is based in reality, and quite bloody.
This makes for a strange combination: a lovers' romance intermingled with the anti-romantic details of a gruesome civil war."
Summaries from: http://watershade.net/wmcclain/rwc-index.html
and The Red Republic (1895) http://www.archive.org/details/redrepublicroman00chamiala. Note: Non-OCR'd scans in PDF and DjVu; text version is an unproofed dump from the DjVu.