I've started reading Barbara Levick's Tiberius the Politician (1976, revised edition 1999).
First thing I came across was the supplemental bibliography of 1999, and what does she list? Massie's Tiberius novel!
I do like the prosopographical excursion into the fates and political/military appointments and positions of adherents of Tiberius on the one side and Julia/Scribonia on the other (Chapter IV: "Rehabilitation: The Final Struggle for the Succession, page 51 ff"), but I'm baffled when the author gets to the Silani:
… Servilia, mother by D. Iunius Brutus of M. Iunius Brutus the Liberator married for a second time D. Silanus, consul, in 62 BC, and became the mother of daughters. One, Iunia Tertulla, was the wife of Cassius the Liberator (as well as being Cato's granddaughter) and survived until AD 22, causing comment by her will: she omitted to mention the Princeps.
Niece surely, not granddaughter?
Levick adds a "warning against reckless prosopographical speculation," listing several cross-overs from within the groups. Overall it seems to show that Tiberius quickly consolidated his support after his return from Rhodes, and even evidences some of it during his exile. It's also interesting to see how many descendants of the old families were still around, contrary to what often is maintained about their disappearance during the various civil wars of the second half of the first century BC. Prosopography can be fascinating: Let's hear it for Ronald Syme!
