In the year 655, when the winters of eighty years had bleached the head of the warlike and ferocious Penda, he again participated in a tremendous conflict which took place on the Field of Victory, or Winwidfield, on the northern bank of the Aire, near Leeds. The occasion of the war was as follows: Adelwald, King of Deira, was threatened by Oswy, King of Bernicia, and perceiving that he could only hope to retain his crown by compassing the ruin of that powerful monarch, he formed a league with the Kings of Mercia and East Anglia, and declared war against Oswy, who, dismayed by so powerful a coalition, strove, by every possible means, to avert the bursting of the storm. All his efforts proving futile, he humbled himself in fervent supplications for victory on the solemn eve of the impending battle, and recorded a religious vow that, in the event of his being delivered from his enemies, his infant daughter, Elfleda, should be devoted to the service of the Holy Church. While Oswy was buried in supplication the shrewd brain of Adelwald was busily revolving the position. Should Oswy be defeated, he would be at the mercy of his allies of Mercia and East Anglia, and his own destruction and the division of his kingdom might be anticipated. To obviate such a disastrous result Adelwald resolved to reserve his own forces, and leave his allies to deal with Oswy, when he might reasonably hope to secure his kingdom against the decimated army, or armies of the victor. On the morning of the 15th of November, the four Kings marshalled their forces, spearmen, and other variously armed infantry and cavalry; and Penda, animated and impetuous, his fiery spirit undimmed by the four score years that had passed over his head, rushed to the attack, and the clash of arms and tumult of war resounded over the field as the troops of Oswy nobly sustained the fierce assault. At this juncture, the crafty Adelwald, assured that the deadly game would be continued to the bitter end, began to retire his troops, and the Mercians, losing heart under the suspicion of his treachery, relaxed their efforts, and commenced a hasty and confused retreat. Penda and his numerous chieftains appealed to them, and strove to restore their broken ranks, but in vain. Oswy pressed them hard; smote them with fierce charges of cavalry, and with the rush of his serried spearmen bore down all resistance. The Kings of Anglia and East Mercia were put to the sword, and their armies decimated and scattered. Oswy, secured in the possession of life and throne, exulted in the signal victory which had blessed his arms. Amid the lifeless thousands that encumbered the sanguinary field, twenty-eight vassal chieftains of the highest rank had fallen with their Kings. Oswy satiated his regal ambition by taking possession of the realms of his conquered adversaries, but he respected the crown of the crafty Adelwald, who retained the glittering bauble until his death, a few years later.