Sorely pressed by the barons in 1215, John sought refuge within the castle, and in the same year signed the two charters, Magna Charta and Charta de Foresta, at Runnymede -- a plain between Windsor and Staines. A curious account of his frantic demeanour, after divesting himself of so much power and extending so greatly the liberties of the subject, is given by Holinshed: -- "Having acted so far contrary to his mind, the king was right sorrowful in heart, cursed his mother that bare him, and the hour in which he was born; wishing that he had received death by violence of sword or knife instead of natural nourishment. He whetted his teeth, and did bite now on one staff, now on another, as he walked, and oft brake the same in pieces when he had done, and with such disordered behaviour and furious gestures he uttered his grief, that the noblemen very well perceived the inclination of his inward affection concerning these things before the breaking-up of the council, and therefore sore lamented the state of the realm, guessing what would follow of his impatience, and displeasant taking of the matter." The faithless king made an attempt to regain his lost power, and war breaking out afresh in the following year, a numerous army, under the command of William de Nivernois, besieged the castle, which was stoutly defended by Inglehard de Achie and sixty knights. The barons, however, learning that John was marching through Norfolk and Suffolk, and ravaging the country, hastily raised the siege and advanced to meet him. But he avoided them, marched to Stamford and Lincoln, and from thence towards Wales. On his return from this expedition he was seized with the distemper of which he died.

Henry the Third was an ardent encourager of architecture, and his reign marks the second great epoch in the annals of the castle. In 1223 eight hundred marks were paid to Engelhard de Cygony, constable of the castle, John le Draper, and William the clerk of Windsor, masters of the works, and others, for repairs and works within the castle;. the latter, it is conjectured, referring to the erection of a new great hall within the lower ward, there being already a hall of small dimensions in the upper court. The windows of the new building were filled with painted glass, and at the upper end, upon a raised dais, was a gilt throne sustaining a statue of the king in his robes. Within this vast and richly decorated chamber, in 1240, on the day of the Nativity, an infinite number of poor persons were collected and fed by the king's command.

During the greater part of Henry's long and eventful reign the works within the castle proceeded with unabated activity. Carpenters were maintained on the royal establishment; the ditch between the hall and the lower ward was repaired; a new kitchen was built; the bridges were repaired with timber procured from the neighbouring forests; certain breaches in the wall facing the garden were stopped; the fortifications were surveyed, and the battlements repaired. At the same time the queen's chamber was painted and wainscoted, and iron bars were placed before the windows of Prince Edward's chamber. In 1240 Henry commenced building an apartment for his own use near the wall of the castle, sixty feet long and twenty-eight high; another apartment for the queen contiguous to it; and a chapel, seventy feet long and twenty- eight feet wide, along the same wall, but with a grassy space between it and the royal apartments. The chapel, as appears from an order to Walter de Grey, Archbishop of York, had a Galilee and a cloister, a lofty wooden roof covered with lead, and a stone turret in front holding three or four bells. Withinside it was made to appear like stone-work with good ceiling and painting, and it contained four gilded images.

This structure is supposed to have been in existence, under the designation of the Old College Church, in the latter part of the reign of Henry the Seventh, by whom it was pulled down to make way for the tomb-house. Traces of its architecture have been discovered by diligent antiquarian research in the south ambulatory of the Dean's Cloister, and in the door behind the altar in St. George's Chapel, the latter of which is conceived to have formed the principal entrance to the older structure, and has been described as exhibiting "one of the most beautiful specimens which time and innovation have respected of the elaborate ornamental work of the period."

In 1241 Henry commenced operations upon the outworks of the castle, and the three towers on the western side of the lower ward -- now known as the Curfew, the Garter, and the Salisbury Towers -- were erected by him. He also continued the walls along the south side of the lower ward, traces of the architecture of the period being discoverable in the inner walls of the houses of the alms-knights as far as the tower now bearing his name. From thence it is concluded that the ramparts ran along the east side of the upper ward to a tower occupying the site of the Wykeham or Winchester Tower.

The three towers at the west end of the lower ward, though much dilapidated, present unquestionable features of the architecture of the thirteenth century. The lower storey of the Curfew Tower, which has been but little altered, consists of a large vaulted chamber, twenty-two feet wide, with walls of nearly thirteen feet in thickness, and having arched recesses terminated by loopholes. The walls are covered with the inscriptions of prisoners who have been confined within it. The Garter Tower, though in a most ruinous condition, exhibits high architectural beauty in its moulded arches and corbelled passages. The Salisbury Tower retains only externally, and on the side towards the town, its original aspect. The remains of a fourth tower are discernible in the Governor of the Alms-Knights' Tower; and Henry the Third's Tower, as before observed, completes what remains of the original chain of fortifications.

On the 24th of November 1244 Henry issued a writ enjoining "the clerks of the works at Windsor to work day and night to wainscot the high chamber upon the wall of the castle near our chapel in the upper bailey, so that it may be ready and properly wainscoted on Friday next [the 24th occurring on a Tuesday, only two days were allowed for the task], when we come there, with boards radiated and coloured, so that nothing be found reprehensible in that wainscot; and also to make at each gable of the said chamber one glass window, on the outside of the inner window of each gable, so that when the inner window shall be closed the glass windows may be seen outside."

The following year the works were suspended, but they were afterwards resumed and continued, with few interruptions; the keep was new constructed; a stone bench was fixed in the wall near the grass-plot by the king's chamber; a bridge was thrown across the ditch to the king's garden, which lay outside the walls; a barbican was erected, to which a portcullis was subsequently attached; the bridges were defended by strong iron chains; the old chambers in the upper ward were renovated; a conduit and lavatory were added; and a fountain was constructed in the garden.

In this reign, in all probability, the Norman Tower, which now forms a gateway between the middle and the upper ward, was erected. This tower, at present allotted to the house keeper of the castle, Lady Mary Fox, was used as a prison-lodging during the civil wars of Charles the First's time; and many noble and gallant captives have left mementoes of their loyalty and ill fate upon its walls.

In 1260 Henry received a visit to Windsor from his daughter Margaret, and her husband, Alexander the Third, King of Scotland. The queen gave birth to a daughter during her stay at the castle.

In 1264, during the contest between Henry and the barons, the valiant Prince Edward, his son, returning from a successful expedition into Wales, surprised the citizens of London, and. carrying off their military chest, in which was much treasure, retired to Windsor Castle and strongly garrisoned it. The Queen Eleanor, his mother, would fain have joined him there, but she was driven back by the citizens at London Bridge, and compelled to take sanctuary in the palace of the Bishop of London, at St. Paul's.

Compelled at length to surrender the castle to the barons, and to depart from it with his consort, Eleanor of Castile, the brave prince soon afterwards recovered it, but was again forced to deliver it up to Simon de Montford, Earl of Leicester, who appointed Geoffrey de Langele governor. But though frequently wrested from him at this period, Windsor Castle was never long out of Henry's possession; and in 1265 the chief citizens of London were imprisoned till they had paid the heavy fine imposed upon them for their adherence to Simon de Montford, who had been just before slain at the battle of Evesham.

During this reign a terrific storm of wind and thunder occurred, which tore up several great trees in the park, shook the castle, and blew down a part of the building in which the queen and her family were lodged, but happily without doing them injury.

Four of the children of Edward the First, who was blessed with a numerous offspring, were born at Windsor; and as he frequently resided at the castle, the town began to increase in importance and consideration. By a charter granted in 1276 it was created a free borough, and various privileges were conferred on its inhabitants. Stow tells us that in 1295, on the last day of February, there suddenly arose such a fire in the castle of Windsor that many offices were therewith consumed, and many goodly images, made to beautify the buildings, defaced and deformed.

Edward the Second, and his beautiful but perfidious queen, Isabella of France, made Windsor Castle their frequent abode; and here, on the 13th day of November 1312 at forty minutes past five in the morning, was born a prince, over whose nativity the wizard Merlin must have presided. Baptized within the old chapel by the name of Edward, this prince became afterwards the third monarch of the name, and the greatest, and was also styled, from the place of his birth, EDWARD OF WINDSOR.