This book details the three "leadership" clans of the Dark Ages, the Lasombra, Tzimisce and Ventrue.
The Lasombra section was fairly interesting. It describes the split in the Lasombra between Christian and Muslim, their secret society known as the Amici Noctis, and a host of new powers. The elder-only powers are a little over the top (which is the tendency in WW) but there are several powers which mix Lasombra disciplines at lower levels, which means young'uns can use them too.
The Tzimisce was fascinating. It gave a good feel of how a voivode's estate is run and provides a list of the DA ghoul families, which didn't all make it to the modern day. Finally a write-up on Koldunic sorcery! It needs more detail, though, and I was a little disappointed that Koldunic sorcery seems to be Thaumaturgy with different names. There are elder powers here, too, ranging from the twisted to the obscene. This was, to me, the most interesting part of the book.
The Ventrue section is pretty boring, but there is minor interest to be found in the sections on the factions within the Ventrue, especially the Merchant Princes.
All in all, a very worthwhile book. I recommend it to anyone who plans to run a Dark Ages game.