Visitors to the ramparts of Edinburgh Castle cannot fail to be impressed by the sheer bulk of a medieval siege cannon that faces north over Princes Street. Mons Meg, as the gun is affectionately known, has had a long and chequered career.

In 1449 a pair of massive siege guns called bombards were manufactured in Mons, a town now in modern-day Belgium, for Phillip the Good, Duke of Burgundy. In the same year Phillip's niece, Mary of Gueldres, married King James II of Scotland. The two events were not entirely unconnected for, in 1457, Phillip sent the two guns to Scotland as a gift to his nephew by marriage. Unfortunately only the one at Edinburgh Castle has survived to the present.

Mons Meg was a powerful lady in her prime, weighing in at something in excess of 6 tons. The powder charge of 120 lbs could apparently propel the 330 lbs 'gunstone' over 2½ miles. She had her limitations, however. It took over 100 men to handle her and was unlikely to be moved more than about 3 miles in a day. Added to that, a firing rate of only 8 shots in a day meant that she became obsolete as a weapon of war and was returned permanently to Edinburgh Castle in the 16th century for use on ceremonial occasions.

Although Mons Meg was a gift to James II, records of her use relate in the main to the reign of James IV. She was used by him against some of his rebellious nobles, including being in action at the surrender to the king of Dumbarton Castled by the Earl of Lennox in 1489 and, nine years later, she was in use against the English in Northumberland at the siege of Norham Castle.

In her ceremonial role Mons Meg was central to salutes fired from Edinburgh Castle on important state occasions. In 1558 she was fired as part of the celebrations on the marriage of Mary Queen of Scots to the French Dauphin, and it was said that the 'gunstone' was recovered almost 3 miles away. To celebrate the birthday in 1681 of the Duke of Albany, later to become James VII and II, Mons Meg was again fired but this time the barrel of the gun exploded. After these ceremonies she was dumped outside the Castle and lay there rusting until, in 1754, she was removed to the Royal Armouries in the Tower of London, along with other obsolete guns and weapons confiscated after the Battle of Culloden. At some point in the ensuing 75 years the barrel was repaired although the repair, towards the rear of the gun, is still noticeable.

The successful campaign to have Mons Meg returned to Edinburgh was a joint effort between Sir Walter Scott and the Society of Antiquaries of Scotland, culminating in the great gun being landed at Leith on 9th March 1829. An escort of three troops of cavalry and the 78th Highlanders accompanied her through the city and into the Castle. Contemporary accounts record that "the Royal standard was raised, the bells in St Giles were rung and bands played to cheering crowds" . And there Mons Meg stood, near to St Margaret's Chapel, the highest point of the castle rock, for the next 150 years for visitors to wonder at. In 1980, however, prompted by fears at the deteriorating condition, she was removed to the castle vaults. Modern techniques of conservation in the ensuing two decades resulted in her being returned to her position on the ramparts, fully protected against the weather.

A small ceremony marked the occasion on 31st July, 2001. Representatives of the Scottish regiments guarded her, a three-gun salute was fired from the Half-Moon Battery, and there was a trumpet fanfare to welcome her return. In reply Mons Meg was 'fired, for possibly the last time, to acknowledge that she was back, not with the 330 lbs stone ball that she fired in her prime but with a small powder charge inside the barrel. As the Director of Historic Scotland, Graeme Munro, said on that day, "This ceremony hopes to symbolise Mons Meg's place in Scotland's story. We are delighted to be able to bring her back to the ramparts, where a sense of her great size and construction is best appreciated." I will leave the last word to Edinburgh resident Malcolm Paterson, who said, "I used to come here as a kid and, now that she's back, I can bring my kids to see her. She's one of the great sights here for visitors" .