Actually the 'Seigneur of the Swans' has people to carry out the medieval tradition for him
(Newser) -
Scarlet uniforms flashed against the riverbank. Wooden skiffs glided in formation. A young swan, gently lifted from the water, was measured, inspected, and released. The annual five-day census of swans belonging to King Charles III—known as Swan Upping—began Monday on the River Thames to assess their health. One...