Tortoiseshell has been widely used for making decorative objects since ancient times.
It is taken mainly from the larger species of tortoise and turtle, particularly the hawksbill sea turtle, which is now critically endangered.
There has been a worldwide ban on trade in the material since 1973.
The bowl is thought to have been part of an immense bequest from Elizabeth, Countess of Devonshire (1619-1689), to her daughter Anne, Countess of Exeter (1649-1703).
This is recorded in an inventory known as the 1690 Devonshire Schedule, or Deed of Gift, although it does not seem to specifically mention this item.
