The Stone of Destiny was kept by the monks of Iona, the traditional headquarters of the Scottish Celtic church, until Viking raiding caused them to move to the mainland, first to Dunkeld, Atholl, and then to Scone.
He had already taken the Scottish regalia from Edinburgh, which included Saint Margaret's Black Rood relic, but to confiscate an object so precious to the Scots, and so symbolic of their independence, would be a final humiliation.
With three months to anticipate Edward's arrival, there was ample time and incentive for a switch to be made, in order to protect the original relic.
Nigel Tranter believed the True Stone was originally hidden by the Abbot of Scone, and eventually entrusted to the care of Aonghus Óg Mac Domhnaill, by Robert the Bruce.
[3] One legend records that after the True Stone was given into the keeping of Aonghus Óg, its keepership passed into the branch of the clan who settled in Sleat.
A descendant of this line, C. Iain Alasdair MacDonald, wrote to Tranter, claiming he was now the custodian of the Stone, which was hidden on Skye.
None of the men being injured, curiosity induced them to clear out the subterranean recess, when they discovered among the ruins a large stone, weighing about 500l [230 kg].
[...] The curious here, aware of such traditions, and who have viewed these venerable remains of antiquity, agree that Macbeth may, or rather must, have deposited the stone in question at the bottom of his Castle, on the hill of Dunsinane (from the trouble of the times), where it has been found by the workmen.
[10] This scenario receives support from a plaque placed in St Columba's Parish Church in Dundee, which claims to mark the site of the 'Stone of Scone', given to them in 1972 by 'Baillie Robert Gray'.
[8] A scanray examination conducted by the Home Office Police Scientific Development Branch in 1973 confirmed the presence of 'three metal rods and sockets, one being at right angles to the other two'.