From John D'Earley's biographically poem, "The History of William the Marshal," it appears that the Siege of the so-called Castle of Newbury (probably Hamstead Marshall) must have lasted more than two months, and was signalised by many notable exploits, of which the following is a short summary:

The King summoned the Constable to deliver up the castle, which he refused to do; an assault was then made on the garrison, and repulsed. The Royalists thereupon blockaded the castle, upon which the defenders requested a truce to consult their commander, John Marshal. It was granted for one day only, but an extension was demanded of the King, in order that the Marshal might communicate with the Empress. Stephen then consented on the condition that one of the sons of the Marshal was surrendered as an hostage. They, therefore, sent the Marshal's second son, William, to whom the poem chiefly relates, and the interest is henceforward centred in this youth, who becomes the hero of the story. The quarrel between Stephen and Matilda, and the narrative of the siege being but accessories surrounding this event. John Marshal having yielded his son to Stephen, hastened to make 'Newbury' castle a strong garrison and, when the time of the truce expired, he refused to deliver up the stronghold and is represented to have risked the life of his son. Stephen decided that the boy should be hung and, for fear that someone might be tempted to save him, he accompanied the lad to the place of execution. On the way, the boy, who knew nothing about the treatment they were preparing for him, seeing the Earl of Arundel hold a bright javelin in his hand, said to him, " Sire, give me that javelin!" The King, touched by the prattling innocence of the child, had him taken back to the camp. But sometime after, the King was persuaded to have the child thrown from a military sling for the throwing of stone balls, when the boy's childish innocence again saved his life. " God," said he, " What a beautiful swing. It is just my size." "Take him away," said the King, " one would have a heart of iron to see such a child perish." One sees that Stephen was sensible to the graces of infancy. Further on, we see him to still better advantage, when engaged in playing a childish game, aux chevaliers, with his young prisoner, that is to say, with the blooms of a plant which grew in the open kind around the castle, and is described as having a broad and pointed leaf. It was probably the common plantain (plantana lanceolata), with which children still amused themselves into the early 20th century, in the same manner described in the poem. The game was called " Playing at Soldiers".