During the 17th century the walled city of Dundee was regarded as the most secure place in Scotland, the wealth of the viscount of Newburgh and the earls of Tweeddale and Buccleuch were entrusted for safekeeping and the city of Edinburgh even lodged its gold reserves within the city walls.

Dundee's monarchist stance had enraged Oliver Cromwell, who had overcome royalist forces south of the border in 1649. The attack was part of a campaign to crush remaining royalist support at the end of the 1642-51 civil wars.

Monck decided to make an example of Dundee. He took the town, slaughtered the garrison and allowed his troops to plunder the town for two days. 2,000 were massacred including 200 women and children. Dundee's oldest building Gardynes land is missing a storey, a possible result of destruction caused by the 1651 siege and occupation of the town by Cromwellian forces led by General Monk.

As Dundee burnt, Monck ordered his men to commandeer more than 60 ships from Dundee's harbour and loaded them with an estimated £2.5m worth of coins, plus tons of valuable trophies including ornamental plates made of precious metals, religious artefacts stolen from churches and monasteries around Scotland.

But as they set sail in September 1651 a storm blew across the Tay estuary. All 60 of the ships sank in heavy seas as, crowded together, they were driven into one of the river's notorious sandbanks. It is not known how many died in the disaster, although Monck survived.

Monck's chaplain. Dr Gumble, wrote: "The ships were cast away within sight of the town, the great wealth perished."