It is commonly attested by scholars that Herod the Great executed his sons, Alexander & Aristobulus, in the year 7 BC. I do believe this date is solid, but how do we know?. In post #1 of this series, I agreed with Daniel Schwartz who said it gets repeated blindly too often. At face value, I admitted, it could have been late 8 BC. But in post #2, I began a closer look at the travel logistics involved. As it turns out, the old estimate seems to hold up extremely well.
What follows is an awful lot of work, but it may produce unexpected benefits. Read on, and we'll see...
Herod's man Olympus sails to Rome in 8 BC, but Augustus left to make war in Germany some time before June. Olympus also went the long way, stopping at Cilicia en route, so there's no way Olympus catches the Emperor in time. (Let alone, whether Nicolas could have done so first - on which, see post #2.) So Olympus has to wait until after the campaign - July stretches the imagination, but for argument's sake, let's pretend Caesar quit half way through the season. There's a lot else that still has to happen, before Herod can kill A&A.
After Nicolas AND Olympus get their hearings with Caesar, the Emperor sends a letter to Herod with advice about A&A. (~48 days) Then, Herod has to call a council of important men, including the Governor of Syria. Assuming everyone confirms the first suggested date, and comes right away, the fastest possible gathering is about two weeks out. (The absolute minimum time now is ~60 days, total.) The council meets at Berytus, after which Herod himself went to Tyre. (another two days) And now we come to the critical point. At Tyre, Nicolas arrives by ship from Rome, a bare minimum of 62 days after Olympus met Caesar, but probably much more.
Can this reunion at Tyre happen in 8 BC? It's conceivable, but not likely. For Nicolas to arrive at Tyre before November, Augustus would have to be back in Rome before September. That would be odd for a campaigning season, especially since we have no particular reasons for suspecting Augustus quit Germany early this year. Far from it - the campaign has to be reconstructed from several ancient sources (H/t Peter Swan). It doesn't sound like it was extremely quick.
Velleius [who, granted, always exaggerates in praise of Tiberius] says Tiberius traversed and subdued "every part of Germany". Suetonius & Dio Cassius tell us Augustus & Tiberius [together] relocated 40,000 Suebi & Sugambri tribespeople, settling them on the Gaulish side of the Rhine. Tacitus says it was "policy, more than force" that won the settlements with these tribes, but whatever Tiberius did won him a Triumph, which was not celebrated until the following Spring. No time for an Autumn parade suggests Tiberius stayed almost until winter, but evidently the Emperor himself stayed at least long enough to direct the settlements of the Sugambri into Gaul. Finally, Dio adds that Augustus, back in Rome, accepted the permanent commemoration of his birthday, September 28th, but preferred that the month of Sextilis be re-named as "August" because he had won so many battles in that month.
All these clues put together suggest the Emperor was still in Germany during at least part of August, becoming victorious at yet another campaign in that month. It also sounds like Caesar must have been in Rome early enough to accept the plans for celebrating his birthday, and if Tiberius himself stayed longer in Northern Europe that could explain why the Triumph was postponed until after winter. Leaving Germany after early August would put Augustus back in Rome by mid-September - but not before September.
The probable timeline for Augustus makes impossible even the fastest conceivable timeline for Nicolas-to-Tyre. And faster than plausible timelines for Augustus still require the fastest conceivable timeline for Nicolas-to-Tyre, and/or a very late arrival date, stretching the bounds of sailing season beyond practical reasonability. "The Fast" when Luke sailed to Rome [59 AD] fell on October 6th. For Nicolas to beat that date, Augustus would have to leave Germany around late June!
If there were any other reason to believe the execution of Alexander & Aristobulus happened in 8 BC, we might be bound to stretch plausibility on these considerations - but there is not, so we are not. The sequence of events in Josephus falls into the calendar more neatly the more we include events from other sources. As often happens, travel-time and sailing season offer the most restrictive data, which is therefore the most helpful.
Nicolas of Damascus must have waited in Rome during the winter of 8/7 BC. There are too many variables for things to happen any faster. It seems Herod, for whatever reasons of his own, drug his feet a bit in getting the council together. Maybe, in Rome, Olympus hadn't gotten to see Augustus right away after his return. And surely Augustus, as would have been extremely characteristic for the Emperor, deliberated a while before writing his letter of advice on such a weighty matter. Whenever Herod finally did call the council, it's likely the Governor, Sentius Saturninus, didn't have a free moment in his immediate schedule, or perhaps not for a while. On top of all this, maybe Herod just couldn't make a final decision, emotionally, without his chief advisor's personal input - and scheduled the council for a time near his arrival. At the very least, the King of the Jews did decide to coordinate with Nicolas one more time, sending word to him at some point that Tyre would be their meeting site. Any or all of these additional factors add significant amounts of extra time to our considerations. In sum, based on all of this evidence, there's simply no way Nicolas could plausibly sail back from Rome in 8 BC.
Therefore, Nicolas arrived at Tyre in the spring of 7 BC. Some weeks after his arrival [May/June?], Herod gave the order to execute his sons, Alexander & Aristobulus. Not only is the old estimate solid, but those scholars should be totally vindicated for whom this date has been "accepted as canonical".
On a personal note, I'm grateful for the footnote of Daniel Schwartz. This has been fantastic exercise. And it's not over yet...