The High Sheriff of East Sussex, Mrs Jane King, made a county proclamation of the new sovereign outside the main reception at County Hall, in St Anne's Crescent, Lewes at 1pm.
People were invited to gather to hear the announcement by the High Sheriff.
The national anthem was then sung and concluded with three cheers for the King.
The tradition of the proclamation dates back many centuries to before modern communications when the local announcement was often the first time people learned of the accession of a new monarch.
Following Buckingham Palace’s announcement of the death of Her Majesty Queen Elizabeth II last Thursday (September 8), a period of National Mourning has started and will continue until the end of the day of the State Funeral.
1. County Proclamation of the new King at County Hall, Lewes (Photo by Jon Rigby)
County Proclamation of the new King at County Hall, Lewes (Photo by Jon Rigby) Photo: JON RIGBY / PHOTOGRAPHER / 07850
2. County Proclamation of the new King at County Hall, Lewes (Photo by Jon Rigby)
County Proclamation of the new King at County Hall, Lewes (Photo by Jon Rigby) Photo: JON RIGBY / PHOTOGRAPHER / 07850
3. County Proclamation of the new King at County Hall, Lewes (Photo by Jon Rigby)
County Proclamation of the new King at County Hall, Lewes (Photo by Jon Rigby) Photo: JON RIGBY / PHOTOGRAPHER / 07850
4. County Proclamation of the new King at County Hall, Lewes (Photo by Jon Rigby)
County Proclamation of the new King at County Hall, Lewes (Photo by Jon Rigby) Photo: JON RIGBY / PHOTOGRAPHER / 07850