When we think of the Middle Ages in Scottish history our minds turn at once to the kingdom that doggedly maintained its independence against English aggression for centuries.

The king of England claimed authority over the entire island of Britain. The Scots, by contrast, declared they were a separate people who had been free since ancient times.

You would expect, therefore, that Scots were keen to avoid identifying themselves as British in case this compromised their independence. This could explain why the Irish origins of the Scots feature prominently in Scottish histories written at the time, such as John Of Fordun's Chronicle in the 1380s. It comes as a surprise, therefore, to find that some Scots, at least, saw no contradiction between Scottish independence and identifying with Britain.

Fordun himself saw it as the duty of kings of Scots "to maintain the traditions of the brilliant fighting force of the victorious fighting island that is of the Scots and the English". Thomas Barry, in his poem on the Scottish victory at Otterburn (1388), written shortly after the battle, expresses his grief at the death of the earl of Douglas in strikingly British terms. He bewails how "the island home of the British contains two most warlike kingdoms, from which is banished every benefit of peace by the craft of the Devil".

This challenges the assumption Scottish independence and Britishness are necessarily incompatible. To understand this better, we need to look at the beginning of Scotland itself. The Gaelic word for Scotland, Alba, originally meant Britain. The earliest likely example of Alba used for northern Britain is as a term for Pictland. This is found in a listing of Pictish regions in a Gaelic verse datable to the 870s at the latest. We could translate Alba in this instance as Pictland but that would lose a crucial part of the meaning. It is likely the Picts thought of Pictland as Britain because they regarded themselves as the "real Britons".

Pictland was not the only country to call itself Britain. Brittany, for example, is simply Britannia in Latin. In each case Britain made sense because its inhabitants identified themselves as indigenous to Britain. In the case of the Picts, this presumably continued when they became Gaelic speakers, and would explain why Alba, Britain, became established as the kingdom's name from about 900.

At that stage Alba typically referred to the landmass north of the Forth. In Latin it was often Scotia, a name that signalled its Gaelic identity. The king of Alba also ruled regions south of the Forth. Neither the king nor his subjects, though, thought of the kingdom as a single country yet. This first began to happen in the 1180s among major landowners. They had lands in England and so, in practice, were British.

But the last thing they wanted was for Scotland to be the same as England. From the mid-1170s England became radically more centralised in ways that made major landholders feel threatened. It was in their interests to emphasise the Scottish kingdom was distinct from England, and to see it as a single country with its own laws - laws that safeguarded the power of lords over their tenants.

The common thread in each case is that Britishness was linked to an assertion that Scotland was separate. Fordun had a vision of Britain as a single kingdom, but only because he claimed kings of Scots were the heirs of the Anglo-Saxon dynasty ejected by the Normans in 1066. British and Scottish independence were compatible because Scotland was seen as a different kind of Britain from England.

The Picts saw themselves as the "true" Britons, and therefore fundamentally different from other Britons. The lords with lands in England as well as Scotland wanted to emphasise Scotland was a single country on a par with and distinct from England. Could a Yes vote be an assertion of a distinct way of being British, rather than a rejection of Britishness as such?