If you visit Inveraray Castle, 60 miles from Glasgow, you might find the 13th Duke of Argyll manning the tills in the gift shop. Torquhil Campbell, 50, head of Clan Campbell, is a down-to-earth chief.

Inveraray Castle is home to one of the most important private collections of historical archives in all of Britain—a collection of records, documents and diaries, dating back to the 13th century.