For many, it seems that a margin of victory of 52 to 48 is less than compelling. In Wales, it is splendidly ironic that some of those questioning the validity of the 2016 referendum result are the same people who rejected any such questioning in 1997 when Wales voted for devolved government by 50.3 to 49.7 – a margin so narrow that the verdict could not be confirmed until the very last vote had been counted.

Wales: can the slumbering dragon awake? | Simon Jenkins Read more

There have been four cardinal events in Welsh politics since the second world war. This week Wales is marking, celebrating or bewailing (take your pick) the most recent of them, the poll held in accordance with the Referendums (Scotland and Wales) Act 1997. This was one of the first pieces of legislation passed by the Labour administration of Tony Blair. But it is difficult to understand the peculiar circumstances of 1997 without appreciating what went before.

The first event of note was the creation of the Welsh Office (now the Wales Office) in 1965 following the appointment of James Griffiths, one of Labour’s forgotten heroes, as the first secretary of state for Wales. Griffiths had slowly come to the view that Wales needed a Whitehall department wholly dedicated to finding Welsh solutions to Welsh problems. Griffiths was a highly respected figure but even he found it difficult to get Whitehall to take Wales seriously. Imagine how difficult it must have been for some of his less impressive successors.

Griffiths’ Labour allies – including his successor, Cledwyn Hughes – were both helped and hindered in 1966 by the momentous victory of Plaid Cymru’s Gwynfor Evans in the Carmarthen parliamentary byelection. Harold Wilson, the prime minister, suddenly became far more receptive to Welsh calls for economic aid. Labour was terrified of a major Plaid advance and started thinking seriously about developing a devolution strategy.

This led eventually, thanks in part to the Kilbrandon report, to the Wales Act 1978, which set out the terms for the referendum held on St David’s Day 1979. The referendum was notable for two reasons: the crushing rejection of Labour’s plans by a margin of 80 to 20, and the relentlessly toxic nature of the campaign itself. Set against that base standard, the Brexit debate has been an exercise in gentle merriment.

The experience of the ensuing Thatcher years convinced many of the Labour doubters of 1979 that devolved government might after all provide some political protection. On this basis they went ahead with the referendum plans in 1997 and – by a whisker, thanks to Blair’s immense popularity at the time – they carried the day.

I spent nearly 15 years as a political journalist at Westminster, and witnessed at first hand the way Wales was treated before devolution arrived. The Welsh select committee did some important and valuable work, but parliamentary debates on Welsh matters could be cancelled for the flimsiest reason, a monthly session of Welsh questions was often a jeering pantomime, and Welsh affairs were generally regarded as a nuisance or worse. There were many Welsh MPs who worked hard to make things better, but they worked within an antiquated system that thwarted their ability to change things.

There are still people who think Wales was better governed when Westminster grudgingly devoted some time to Welsh issues, but I am not one of them. This is hardly a controversial statement: it is instructive to note that every major political party now fully endorses the devolved settlement. This is not to say that people are happy with the performance of the national assembly and Welsh government. That is a wholly different matter, and Wales certainly needs far more scrutiny by journalists of its government and politicians.

As Brexit rolls on, the degree to which Whitehall respects the devolved settlement is more relevant than ever

It was the late John Smith who firmly committed Labour to a policy of devolving power that – in his compelling assertion – reflected the “settled will” of the Scottish people. Welsh voters have been on a rather more tortuous journey. The “settled will” of 1979 was one of vehement opposition. By 1997 it had changed to uncertainty. And now, on the eve of this 20th anniversary of the referendum, every credible survey of opinion suggests that the national assembly and Welsh government are widely accepted by Welsh voters.

The biggest change of the past few decades has been a fundamental change of perspective. As the Brexit process rolls on, the degree to which Westminster and Whitehall respect the devolved settlement is more relevant than ever. But devolved government – “government closer to the people” in Smith’s words – is here to stay.

• Huw Edwards will present 20 Years of Power to be broadcast on BBC1 Wales on Wednesday 20 September