were defensible
even at that time. Of his building perhaps nothing 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 mediaeval 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 connected episode of April-June 1215, 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 importance of the few old national roads as
late as the reign of John, and that power of the defensive, even in
the field, which made general and strategic, as opposed to tactical,
attack so cautious, decisive action so rare, and when it _was_
decisive, so thorough.

This book is no place wherein to develop a theme which history will
confirm with regard to the aristocratic revolt against the vice and
the genius of the third Plantagenet. The strategy of the quarrel alone
concerns us.

When John's admirable diplomacy had failed (as diplomacy will under
the test of arms), and when his Continental allies had been crushed at
Bouvines in the summer of 1214, the rebels in England found their
opportunity. The great lords, especially those of the north, took oath
in the autumn to combine. The accounts of this conspiracy are
imperfect, but its general truth may be accepted. John, who from this
moment lay perpetually behind walls, held a conference in the Temple
during the January of 1215--to be accurate, upon the Epiphany of that
year--and he struck a compact with the con