The release of season four of The Crown has reignited the hoary old discussion of the responsibilities of drama when dealing with historical fact. Critics have pointed out that Lord Mountbatten never actually wrote a letter to Prince Charles to upbraid him for refusing to end his affair with Camilla, find a suitable bride and prepare for his destiny as king.
agle-eyed viewers have also hit out at Trooping the Colour scenes where the Queen is wearing the wrong military badges and the actress playing her, Olivia Colman, gives a "shoddy" salute.
But there is one participant portrayed in The Crown whose depiction would appear to be straight on accurate. The IRA.
The depiction of the murder of Mountbatten and those with him that day was less popular drama and more reality TV. The production team gave us a factual run-through of the appalling callousness of the terrorists' actions.
The sequence began with the royal, who is holidaying in his family home Classiebawn Castle, just over the border in Co Sligo, deciding to take relatives and friends out on his boat Shadow V on August 27, 1979.
The scene is striking in its ordinariness - a fun outing on a summer's day. Mountbatten is heard calling to 'Paul', who is 15-year-old Paul Maxwell, a local lad who had got a summer job as a boatman on Mountbatten's boat. Other children are seen boarding the small craft - one presumably Nicholas Knatchbull, Mountbatten's 14-year-old grandson. A woman, smiling and chatting, is among the party.
All watched over by two IRA men sitting in a battered Ford car overlooking the harbour and waiting to detonate a bomb that they knew could kill everyone on board. Royals, non-royals, children, an old woman.
And they did take the lives of not just Mountbatten, but Paul, Nicholas and the Dowager Lady Brabourne. That same day 18 soldiers were murdered by the IRA at Warrenpoint.
The claim of responsibility is driven home by a voiceover that perfectly captured the malicious glee of the terrorists at their "success". "Thirteen gone and not forgotten, we got 18 and Mountbatten" - which included a reference to those killed on Bloody Sunday but conveniently neglected to mention the murders of two children and an old woman.
Collateral damage is, I think, the phrase they reach for.
Paramilitaries' violence happens the same way regardless of their colour, and many people here will have looked at the Crown and identified with the peculiarly heartless nature of opportunistic attacks on vulnerable people. They too began what they assumed was just another ordinary day only to find themselves engulfed in terror - that's if they were alive at all at the end of it.
Days that began with people opening up their shops, going fishing, driving a bus, heading out for the night to a bar or hotel, or just answering their own front door.
Since then some of these people will have gaped in disbelief at the portrayal of their attackers in numerous TV and film dramas. There's long been a tendency to opt for a glamorised portrayal of the gunman. He is either an idealist or a tortured soul. But The Crown showed the truth about how the IRA operated: often ordinary people were the victims of what was a quite bureaucratic murder machine.
For all the plausibility of lookalikes and soundalikes, there is quite a visible gap between the cold-hearted Charles of The Crown and the florid, rather bumbling and pleasant individual pitching up at official functions. Similarly with the series' emotionally distant HMQ compared to the real one who has found a whole new fan club with those recent documentaries which followed her daily routine around the world. Even Camilla has come out of the daily royal grind of hospital visits, veterans' galas, disadvantaged kids' projects, looking much more approachable and 'aunty-like' than the pouty villainess The Crown portrays.
The difference between The Crown of the 1950s and 1960s and this current bunch is that there are almost nightly programmes of the contemporary royals - we even know where they buy their shoes and get their Christmas decorations. We see them up close. In Ireland, we have seen the Queen and President McAleese, the Duke and Martin McGuinness, indeed Charles himself at the scene of his uncle's murder in a striking act of reconciliation. All this has brought these hitherto remote people right into our daily lives. If anything, the exposure has made them both familiar and comprehensible for the first time.
There is nothing that can be done about the IRA, though. There is no way to nuance two stern men sitting in a car overlooking a harbour where a boatload of people has just pushed off, kids larking about, the ladies settling themselves for a choppy jaunt, and then just flicking a switch that blows the boat to pieces.
Oddly, whatever about the accuracy of the characters of Charles and Di and Camilla and HMQ, The Crown does manage to keep broadly within the tramlines of what we know to be true, keeping it credible and authentic while being dramatic and allowing for some play.
But there's not much you can do with the IRA. Not much nuance there, not a lot of subtlety, nothing a change of tone of voice will achieve or a different shade of lipstick. It's grim, it's menacing and, for all the background chit-chat about history, it's all black-and-white, really. Some drive off into the distance to their next atrocity, full of self-justification, and more are left behind, their lives destroyed, literally dead in the water.
When it came to the crunch, the screenwriters didn't try to dodge that dismal perspective - there is a featureless horror about that opportunistic execution that really just demands to be witnessed by the public for the full futility of it to be felt. The narrative is shameful. The Crown should be applauded for having that much moral gumption at least.