A set of gold rosary beads carried by Mary Queen of Scots at her execution in 1587 was among items worth more than £1m stolen in a raid on Arundel Castle.
The gold and silver artefacts were snatched from the West Sussex castle on Friday night.
Other pieces taken during the raid include coronation cups given by Mary to the Earl Marshal.
An Arundel Castle spokesman said the stolen items were of “priceless historical importance”.
The castle only reopened to the public on Tuesday.