of the many important sites along the Ridgeway is Barbury "Castle". At this point, overlooking the Vale of the White Horse, the path takes a right turn. One leg goes South, the other Eastwards. Barbury dominates this bend, and the valleys below.
It isn't anything we would recognise as a castle today. It was an iron-age hill-fort, re-occupied again and again, re-fortified again and again (it's an outside bet for the site of "Mount Badon", Arthur's decisive victory against the Saxons).
But Barbury's chief claim to fame concerns a major Saxon advance. To understand its significance, we need to go back into the mists where tradition and history merge, and a few miles South.
Some time around 500 A.D., a Saxon adventurer called Cerdic founded a principality or tribe called the Gewisse in the region around Southampton Water, in the valleys of the Test and Itchen Rivers.
This snippet of history/legend (none of this was written down for another 350 years), raises a few problems to the traditional view of the "Coming of the Saxons". For a start Cerdic is a British (Celtic) name - the equivalent of the Welsh Caradoc.
The other problem is that we know something of the Gewisse before Cerdic.
Vortigern, the British commander who had invited the first Saxons into Britain (and who had then fallen out with them), was "Duke of the Gewissei".
It may be that this is pure co-incidence - two languages coming up with two similar names - but it does raise the possibility that the Anglo-Saxon "invasion" was much less of a clash of distinct peoples than was once thought.
Indeed, John Rudmin (Celtic Twilight) argues persuasively that Cerdic was Arthur - a (mostly) British leader of a mixed force, which united South-central England. He cites many interesting parallels in their respective histories.
Andrew Godsell has expanded on the theory.
In any case, Cerdic established his tribe in the lee of the Isle of Wight. He doesn't seem to have pushed out of this new homeland in his lifetime.
However, Cynric (either Cerdic's son or grandson, depending on which source you follow), got the expansionist urge. By 552, he had driven Northwards as far as Salisbury, from which he could dominate a much wider territory, opening up much better farmland for his followers.
Four years later, in 556, Cynric moved again - to defeat British forces at Beranbyrg - Barbury Castle. (He probably used the Ridgeway to move his troops there.) This move opened up even broader horizons - to the East and West.
But none of this would have been particularly important - just another family of Saxon adventurers carving out a territory for themselves - but for the arrival of Cæwlin.
Cynric was joined at Barbury by Cæwlin (after the fighting was over), bringing forces from the West Saxons. At the time, the territory of the West Saxons was in the Lower Thames Valley - around modern Reading.
Subsequent events are shaded in obscurity, but Cynric disappeared from the scene, and Cæwlin became ruler of the Gewisse and Wessex. Thus, the centre of gravity of West Saxon territory moved radically Westwards.
It was here, at Barbury, that the foundation was laid for the Wessex of Kenwulf, Ine, Alfred and Athelstan. And it was this Wessex which formed the nucleus of England.