PRINCE Charles and his wife Camilla are to visit the Hay Festival, it has been announced.

The Royal couple will also visit regeneration projects in Hay-on-Wye during their visit to the booktown, which in the 1970s famously declared itself an 'independent kingdom'.

Their May 23 visit is part of the Telegraph Hay Festival's schools programme on the opening day, Thursday, May 23.

Charles and Camilla will attend some of the events as part of the Hay Fever programme featuring leading children's writers and performers and specially arranged for pupils and their teachers.

Hay Festival says the programme benefits more than 4,000 children from 79 local primary schools.

Roald Dahl illustrator Quentin Blake is among the top names from children's literature scheduled to appear at Hay on May 23.

Camilla, the Duchess of Cornwall, joined author Michael Morpurgo in the Hay Fever tent at the 2011 festival to read from Dog Loves Books by Louise Yates to an audience of appreciative children.