hence Henry led them early in November towards
Chepstow, the centre of the marshal's estates in Gwent. Earl Richard
devastated his lands so effectively that the king could not support his
army on them, and was compelled to move up the Wye valley towards the
castles of Monmouth, Skenfrith, Whitecastle, and Grosmont, the strong
quadrilateral of Upper Gwent which still remained in the hands of the
king's friends. Marching to the most remote of these, Grosmont, on the
upper Monnow, Henry spent several days in the castle, while his army
lay around under canvas. On the night of November 11, the sleeping
soldiers were suddenly set upon by the barons and their Welsh allies;
they fled unarmed to the castle, or scattered in confusion. The
assailants seized their horses, harness, arms and provisions, but
refrained from slaying or capturing them. The royal forces never
rallied. Many gladly went home, giving as their excuse that they were
unable to fight since they had lost their equipment. Henry and his
ministers withdrew to Gloucester. More convinced than ever of the
treachery of Englishmen, the king entrusted the defence of the border
castles to mercenaries from Poitou.

The fighting centred round Monmouth, which Richard approached on the
25th with a small company. A sudden sortie almost overwhelmed the
little band. The marshal held his own heroically against twelve, until
at last Baldwin of Guines, the warden of the castle, took him prisoner.
Thereupon Baldwin fell to the ground, his armour pierced by a lucky
bolt from a crossbow. His followers, smitten with panic, abandoned the
marshal, and bore their leader home. By that time, however, the bulk of
the marshal's forces had come upon the scene. A general engagement
followed, in which the Anglo-Welsh army drove the enemy back into
Monmouth and took possession of the castle. This set the marshal free
to march northwards and join Llewelyn in a vigorous attack upon
Shrewsbury. In January, 1234, they burnt that town and retired to their
own lands loaded with booty. Meanwhile Siward devastated the estates of
the Poitevins and of Richard of Cornwall. Afraid to be cut off from his
retreat to England the king abandoned Gloucester, where he had kept his
melancholy Christmas court, and found a surer refuge in Bishop Peter's
cathedral city. Thereupon Gloucestershire suffered the fate of
Shropshire. "It was a wretched sight for travellers in that region to
see on the highways innumerable dea