At The Battle of the Boyne, Catholic troops were "dead drunk," at least according to an eye-witness account that was auctioned in June 2010.

The Battle of the Boyne was a pivotal event in Irish history when the Catholic King James and his Irish troops were routed by William of Orange.

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The battle took place near the town of Drogheda and has since become the rallying point for millions of Northern Irish Protestants, who celebrate it every year on July 12.

The Battle of the Boyne was fought between the troops of the English King James II, and the Dutch Prince William of Orange, who, with his wife, Mary II, had overthrown James in England in 1688. It resulted in a victory for William.

The Battle of the Boyne (Getty Images)

The Battle of the Boyne (Getty Images)

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The memoirs of Captain John Stevens give a handwritten personal account of James’ Catholic troops. Stevens wrote that they "drank so extravagantly” they were left “dead drunk scattered about the fields” on the morning of the Battle of the Boyne.

He says the soldiers made the fatal mistake in a mix-up over drink rations. He wrote that a consignment of brandy, ordered to fortify the men on the eve of battle, did not arrive until the famous kings were drawing swords.

Stevens wrote the 3,000-word account after taking part in the battle himself. He is also harshly critical of Jacobite commanders who fled the field in front of their men.

However, Grand Secretary of the Orange Order, Drew Nelson, said that it was imperative historians question if Stevens was trying to make excuses as to why they lost the battle. He also said it was up to the officers in charge to regulate how much alcohol the men were allowed to consume.

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“Notwithstanding, this was a fantastic price and demonstrates the interest in artifacts from this period. Several years ago the order bought a letter for $6,052 which was written by King William several days before the battle,” said Nelson.

The Battle of the Boyne: Catholic Jacobite captain's account reveals more than 1,000 Irish Catholic troops were "dead drunk" on July 12 1690.Getty Images