In pictures: Royal Swan Upping takes place along the River Thames in Maidenhead and Windsor

The annual Swan Upping ceremony has seen officials donning bright red uniforms to travel up the Thames.

In a tradition that dates back from the 12th century, the ceremony of Swan Upping sees the Queen’s Swan Marker, David Barber, take an annual census of the swan population on the Thames.

Starting on Monday, Mr Barber, accompanied by other Swan Uppers and volunteers from Datchet-based charity Swan Support, counted all the mute swan cygnets seen on the river.

The boats set off from Sunbury on Monday and will finish in Oxfordshire tomorrow (Friday).

Wendy Hermon, treatment and rescue co-ordinator at Swan Support, said: “I absolutely love it. We are a rescue organisation who find cygnets, and if they hadn’t been ‘uppered’ we wouldn’t know where to return them to.

“We have been doing this for 25 years, we never get bored of it. It’s different cygnets every year, sometimes it makes us laugh when you get some that see the boats coming and they go the other way, they know what’s going on.”

On Tuesday the convoy of boats travelled from Eton to Boveney Lock, then to Boulters Lock before going to Cookham Bridge and ending the day at Marlow Lock.

During the stop at Cook-ham, children from Cook-ham Rise School came to see the Upping for themselves.

The role of the Swan Marker is to count the number of cygnets each year to ensure the swan population is maintained.

So far the number recorded have been as expected, but Mr Barber has warned dog owners to keep their pets away from swans and their nests as they can destroy them.