Calling all armchair generals! Boudica's Last Stand.

[Renatus]

I still find 60-61 more likely.

Why?  Tacitus had been meticulously recounting events each year since AD14, naming the consuls for the year.  He had already named the consuls for AD60, Nero for the fourth time and Cornelius Cossus.  Why should he suddenly go off the rails in AD61?  The only logical reason that I can think of is the use of iam in relation to Turpillianus' retirement from the consulship, if this is interpreted as meaning that he had only just handed over to a suffect consul, which could push the outbreak of the revolt back to AD60.  However, I have put forward what I believe to be a plausible explanation of the wording which preserves Tacitus' dating.

Caesennio Paeto et Petronio Turpiliano consulibus gravis clades in Britannia accepta seems to refer to a single 'disaster'. But it could perhaps also mean a course of events covering some time

Accepta is the past participle of accipio which means literally 'accept' or 'take to oneself' but it can also mean 'bear' or 'endure', which is surely the meaning here.  The 'disaster' from the Roman point of view was the destruction of a colony, a major trading centre and a municipium, and the loss of a large number of Roman and pro-Roman lives, even if it was not as many as 70,000.  That is disaster enough for one year.  I don't suppose he was much concerned with the 'disaster' caused to the rebel tribes by Paulinus' reprisals.