The Thames
remains. The forest to the south, with its opportunities for hunting, and the increasing importance of London (which was rapidly becoming the capital of England) made Windsor of greater value than ever in the eyes of his son. Henry I. rebuilt or greatly enlarged the castle, lived in it, was married in it, and accomplished in it the chief act of his life, when he caused fealty to be sworn to his daughter, Matilda, and prepared the advent of the Angevin. When the civil wars were over, and the treaty between Henry II. and Stephen was signed, Windsor (" Mota de Windsor"), though it does not seem to have stood a siege, was counted the second fortress of the realm.
Of the exact place of Windsor in medieval strategy, of its relations to London and to Staines, and all we have just mentioned, as also of the great importance of cavalry in the Middle Ages, no better example can be quoted than the con- nected episode of April-June 121 5, which may be called — to give it a grandiose name — the Campaign of Magna Charta. It further illustrates points which should never be forgotten in the reading of early English history, though they are too particular for the general purpose of this book — to wit, the way in which London increased in military value throughout the twelfth and thirteenth centuries ; the strategic import- ance of the few old national roads as late as the reign of John,
and that power of the defensive, even in the field, which
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