[3] Having no siege equipment, the Comyns drew off and subsequently joined the main Scottish host at Haddington, which had been assembled to meet the advance of the English army along the east coast.

In March 1298, John was among Scots who deserted the English, finally ending up in Paris, where they appealed for aid to Philip IV of France.

The main task facing the Guardian was to gather a national army to meet an invasion by Edward, anxious to reverse the victory of Stirling Bridge.

On 22 July Wallace's army was destroyed at the Battle of Falkirk, the light horse being driven off at an early stage by the heavy English cavalry.

According to Fordun, John and his kin hated Wallace and appeared on the battlefield only with premeditated treachery in mind – "For, on account of the ill-will, begotten of the sprig of envy, which the Comyns had conceived towards the aforesaid William, they, with their accomplices, forsook the field, and escaped unhurt."

This is set alongside a commendation of Robert the Bruce, who, in Fordun's account, fought on the side of the English and "was the means of bringing about the victory."

This is contested as no Bruce appears on the Falkirk roll of nobles present in the English army, and ignoring Blind Harry's 15th claim that Wallace burned Ayr Castle in 1297, two 19th-century antiquarians, Alexander Murison and George Chalmers, stated that Bruce did not participate in the battle and the following month decided to burn Ayr Castle to prevent it being garrisoned by the English.

The Scots were still fighting on behalf of the absent King John, so Bruce must have paid lip service to the cause, though his royal ambitions were openly known.

[9] English invasions in 1298, 1300, and 1301 had been confined to the south of the country, leaving the north as the chief recruiting ground, and supply base, of the Scottish army.

The Guardian's prestige increased still further when he and Sir Simon Fraser defeated an English reconnaissance force at the Battle of Roslin in February 1303.

In a mood of desperation the Scottish diplomats in Paris, who included Comyn's cousin Buchan, wrote words of encouragement; "For God's sake do not despair...it would gladden your hearts if you would know how much your honour has increased in every part of the world as a result of your recent battle with the English.

Unable to mount an effective resistance, and with his main base threatened with destruction, Comyn entered into peace negotiations, which concluded at Strathord near Perth on 9 February 1304.

Sir Robert Comyn, rushing to aid his nephew, was killed by a blow to the head by Bruce's brother-in-law, Christopher Seton.

[17] Thirteen days after the event, a garbled version of the facts reached the court of Edward I at Winchester, where the murder was reported as "the work of some people who are doing their utmost to trouble the peace and quiet of the realm of Scotland."

Once the picture became clear, Edward reacted in fury, authorising Aymer de Valence, Comyn's brother-in-law, to take extraordinary action against Bruce and his adherents by granting no quarter to them.

The assassination of his father plunged Scotland into a brief but bloody civil war, largely concluded by 1308, but with political reverberations that were to last for decades.