Most historians have assumed that Edward II had certainly been dead for two and a half years at the time of Kent's execution on 19 March 1330, and have forced their discussion of Kent's plans to free him fit into that 'fact', rather than trying to look at the plot with an open mind and wondering why on earth the non-crime of trying to free a dead man merited execution. Here are some of the explanations they have come up with, which are riddled with inconsistencies and contradictions, and my reaction to them.
Also, very importantly, Kent did not act alone in 1329/30. I myself have found more than seventy named men helping and supporting him, and these are just the ones whose involvement was discovered. There may well have been many more. We know from the evidence of Archbishop William Melton's letter of 14 January 1330 declaring that Edward of Caernarfon was then alive and healthy that the mayor of London, Simon Swanland, was involved in the plot, but this was never discovered and Swanland was never implicated or apparently even suspected (Melton and William Cliff, his messenger to Swanland, were both arrested, but kept quiet about Swanland). Additionally, there are entries in the chancery rolls and statements in chronicles which tell us that:
Kent's followers were thought to be particularly numerous in East Anglia; many people in Wales were "of the confederacy" of Rhys ap Gruffydd, one of Kent's most enthusiastic supporters and a very loyal ally of Edward II who had attempted to free him from Berkeley in 1327; that proclamations were issued threatening anyone who said Edward II was still alive with arrest; that Kent had made "confederacies and alliances of men-at-arms and others" in furtherance of his attempt to free his brother; that some of Kent's adherents were gathering in Brabant (where Edward II's nephew John III was duke) and "propose to enter the realm with a multitude of armed men"; that Kent visited Pope John XXII in Avignon in about June 1329 to "see what thing might best be done touching his [Edward's] deliverance"; that within days of Kent's execution, inquisitions were ordered in five southern counties "to discover the adherents of Edmund of Woodstock, late earl of Kent." And so on.
I strongly suspect that we're talking about, at the very least, a good few hundred men supporting Kent in his attempt to free Edward of Caernarfon, maybe a lot more. But yeah, ignore all this wealth of evidence that's in plain view and tell me again how 'stupid' Kent was and how this means that his entire plot was nonsense and simply 'bizarre', and express again your personal incredulity that it could have been real, as though your inability to grasp it is a compelling argument against it. It's very easy to smear one man as 'stupid', 'gullible' and 'credulous' for believing that Edward of Caernarfon was alive in 1329/30, but when there are certainly at least seventy and very possibly many hundreds of people who believed the same thing, among them the highly astute archbishop of York, the bishop and mayor of London, the earls of Mar and Buchan, numerous lords, sheriffs, knights, merchants, clerks, friars, squires...how do you explain away their involvement? Generally, by pretending they didn't exist, or wrongly dismissing them as a mere handful of clerics, or assuming that they were 'misled' or 'deceived' into believing in Edward's survival without bothering to explain or even speculate how or why this deception might have occurred, and thus assume that the men risked imprisonment or exile and forfeiture of all their lands and goods without thoroughly checking the information that Edward was alive. As though all these men, some of whom were in their fifties or more, some of whom were very wealthy and influential indeed, were nothing more than a bunch of obedient robots, who heard the earl of Kent say "Guess what, Edward of Caernarfon is alive!" and immediately gasped "Wow, amazing! Even though I went to his funeral, I believe you instantly without a shred of proof! Let me help you free this dead man! Yes, of course I'll risk forfeiture, imprisonment, exile, maybe even execution, simply on the basis of a story you've told me without ever asking you for proper evidence, even though everyone knows you're a gullible stupid idiot who makes up wildly implausible tales and can't be trusted!"
Kent and/or his supporters didn't really believe Edward was alive but were engaging in wishful thinking: I don't know about you, but pretty often when someone is dead, I pretend years later that I think the person is actually still alive because I miss him and wish he was still alive, to the extent of making plans to free him from the castle where my imagination tells me a dead man would be held and buying him clothes and writing him letters and stuff, even with the threat of being convicted of treason and being executed or imprisoned or exiled from my homeland and losing all my lands and goods except the clothes I stand up in, becoming homeless, losing my income and seeing my family become homeless too. Oh no, wait, I was confused, I don't actually do that. And I'd be very surprised if anyone else on the planet ever did either.
And the same caveat applies: if people knew Kent to be a credulous fool, as is so often claimed nowadays, why did Mortimer and Isabella think anyone would believe him when he said Edward II was still alive? Why would anyone follow a gullible and mentally unsound fool who, hahaha, goes around claiming that the former king is alive, and think he was a plausible leader of the opposition to the ruling pair?
William Melton's letter of 14 January 1330 stating that Edward of Caernarfon was then alive is not evidence that Edward of Caernarfon was then alive: Admittedly the letter is only evidence that Melton strongly believed that Edward was alive, not that he certainly was, but given that highly intelligent, highly experienced and and highly regarded archbishops in their fifties don't generally a) buy clothes, shoes and other provisions for, b) procure a sum of money of gold for, and c) offer to sell all their possessions to help, a dead man, it's a pretty safe assumption that Melton had compelling evidence for Edward's survival, which he didn't commit to the letter. It's clear from the entire letter, in fact, that Melton must have told his messenger William Cliff to inform the recipient, Simon Swanland, mayor of London, quite a few things orally. It's pretty insulting to Melton, who's often considered one of the greatest archbishops in English history, to assume that he was 'easily convinced' and 'deceived' and 'misled' into thinking Edward was alive when you don't have a shred of evidence for this alleged deception. (Who? Why? How?) This theory makes Melton look kind of stupid, doesn't it? Making him look as though he was as credulous as you claim the earl of Kent was. Oh, but Melton really wasn't stupid and credulous. See the pattern here: explain away the whole plot of 1330 by painting those who took part in it as foolish, gullible and easily deceived, their heads in the clouds and away with the fairies with their silly wishful thinking. We in the twenty-first century know and understand the reality of what happened in 1329/30 far better than the men who actually took part in the damn plot, of course we do! I wonder what, if anything, would make modern historians take the notion that Edward was alive past 1327 seriously? A piece of parchment saying 'Dear all, I am still alive at Corfe. Love, Edward of Caernarfon'?
Actually, I don't think that anything at all would convince most historians that Edward was alive past September 1327. When you've spent your entire career stating without reservation that Edward was murdered at Berkeley Castle and that this is as certain a fact as Edward I dying in July 1307 or Edward III dying in June 1377, it becomes rather tricky to say 'Wellllll, actually...'. And so you have to retreat into untenable positions such as claiming that Kent was stupid, and that his followers were no more than a handful of clerics, and all the rest. Ah dear.