The Queen's Swan Marker begins the annual census of swans and their young on the River Thames, monitoring royal babies of a very different kind.
While much of Britain anxiously awaits the birth of the royal baby, on the River Thames the tally began of the… other royal babies.
The annual Swan Upping sees the Queen's Swan Marker, David Barber and his helpers row up the Thames to take the swans up out of the water for an official count.
Barber explains the reason why.
"The Queen has the right to own swans, by royal prerogative, so she can claim any swan swimming in open waters, unmarked in the United Kingdom, but this is mainly exercised on the River Thames."
This ceremony dates back to the 12th century, when swans were an important source of food and a symbol of wealth.
It was then when the British Crown claimed ownership of all the wild swans in its territories, but nowadays the swan census is more to protect and preserve the species.
Per tradition, markers spend five days weighing and tagging all the birds they spot along the 79 mile or 127 kilometer stretch of the Thames.
Last year the Swan Upping did not take place for the first time in hundreds of years because of heavy rain.
The previous census in 2011 counted 114 cygnets, belonging to 30 swan families.