Alistair Moffat, in his book "Before Scotland: The Story of Scotland Before History," has the following to say about the derivation of the name Caledonia,in his opening chapter:

"...Roman historians had a very specific name for northern Britannia. Lucan, Pliny the Elder, Tacitus and Ptolemy all wrote of 'Caledonia' and the name has shown considerable staying power.... 'Caledonia' was a very common early synonym for what became 'Pictavia' or Pictland, or parts of it. In some of the military contexts described by the Romans the Caledonians were the southern Picts centered on Strathmore and the Angus glens, with occasional shifts [mainly by a stroke of Ptolemy's pen] into the Highland massif to the east of the Great Glen. Supplying a little confusion, Tacitus asserts in his account of Agricola's northern campaign of AD 79 to 83 that Caledonia is the whole of the area beyond the Forth and Clyde isthmus...."

"'Caled' appears to be the basis of the name 'Caledonia' and it's meaning is clear, even if its application is not. It meant 'hard' in P-Celtic or early Welsh, and since the first recorded use was in 'Caledonii,' the tribe, it may be that it referred to them, 'the hard men.'"

"Alternatively, the name of Caledonia might have derived from the land inhabited by the Hard Men. The Highland mountains, corries and high glens are often bare, rocky and bleak, and 'caled' might have been the root word of something like 'Rock-Land,' rather in the same way that part of Knoydart is known as 'the Rough Bounds.'"

Moffat also discusses the use of other names for peoples and areas of what are now known as "The British Isles." For example he notes that, "Wales is an English word. It means 'Land of the Foreigners,' or more precisely, the 'Land of the Romanized Foreigners.'" He devotes several pages to the terms 'British' and the 'Cymru' [the Welsh] and the 'Pyrdyn' the Welsh name for the Picts. Also the name 'Alba' or 'Albion' for the island of Britain. Chapter 7, entitled 'Caledonia' covers 59 pages, so I won't try to quote it all here. ;-).

Reiver 2