The Royal Swan Upping is the annual census taking and health check of the king’s swans. It began in the 12th century
15th: Royal Swan Upping on the Thames, inventory and health check of the swans. The swans belong to the king.
More information:
Queen’s website http://www.royalswan.co.uk
Marlow Town Council “Royal Swan Upping 2022”
The Guardian “A cygneture event: what is swan upping?”
Wikipedia https://en.wikipedia.org/wiki/Swan_Upping
