Sticking points on union and disunion

Professor Colley does not allow herself to become bogged down in, for example, the arguments for or against a currency union between an independent Scotland and the rest of the UK, important though that discussion is. In fact, she completely sidesteps all the well-chewed staples of the current debate. Instead, as you would expect from one of the most interesting historians of Britain and its various identities, she takes a longer view.

The book/series examines the relationships between the constituent parts of the United Kingdom since long before it was a united kingdom. It looks at the glue that has held the UK together and considers the factors that are making it come unstuck. As such, it is not about Scottish independence per se. Wales, Ireland, the North-South divide in England, and the UK's relationship with Europe all receive at least as much attention as Scotland. But its themes are directly relevant to the independence debate and it is certainly no mere coincidence the BBC commissioned it for the start of referendum year.

Ms Colley wears her learning lightly. On Scotland she jumps effortlessly from Liz Lochhead's 1987 play Mary Queen Of Scots Got Her Head Chopped Off to Daniel Defoe's tour of Ross and Cromarty (when he pretended to be French to avoid anti-English "mockery or worse"). She dances from James VI styling himself the "King of Great Britain" in 1603 to Winston Churchill's description of his Secretary of State for Scotland, Tom Johnston, as the "King of Scotland". The connections are always thought-provoking. Reading the introduction to Lochhead's play, with its references to "no equal kingdoms" and the "glistening city" down south "that sucked all wealth to its centre," it is striking how Yes Scotland it all sounds. Yet Ms Colley takes issue with the "emphatically different" images of Scotland and England conjured up by the play, whose Elizabeth I, by the way, had more to do with Margaret Thatcher than the Virgin Queen. The two Renaissance princesses had much in common, she argues, as had their homelands. But here is another thought: between 1040 and the Battle of Culloden in 1746 every monarch in London except three either had to repel a Scottish invasion of England or chose to invade Scotland. Or both. Plenty of differences there, then, in a story of constantly shifting borders down the centuries (in the 12th century, we are reminded, Scottish kings ruled not only Northumberland and Cumberland but north Lancashire and parts of Yorkshire). Memories of conflict were among the factors behind parliamentary Union in 1707, Ms Colley believes.

Since then the countries' relationship has been no less complex. The Union has never gone unquestioned, but today the forces that once held it tightly together - the Empire, Britain's mercantile strength, a manufacturing economy - have weakened. In her brief concluding thoughts, Ms Colley argues the break-up of the UK is not inevitable but for it to thrive into the future a more federal arrangement should emerge, with an English parliament in the North and a written constitution for the "revised Union". A devo-max kind of Union, in other words. These "purely private observations of a semi-detached if attentive observer," however, are not the point of the book. Its real strength is its ability to make those interested in the politics of the coming year think afresh about the independence debate and what it is actually all about. What better way to begin 2014?

l Professor Linda Colley's Acts Of Union And Disunion will be broadcast in 15 parts on BBC Radio 4 from January 6 to January 24. The book accompanying the series is published by Profile Books on January 9.