Brown, often called the 'father of landscape architecture,' changed the national landscape and shaped people's understanding of the quintessential English countryside.
The Capability Brown Festival 2016 is the first-ever nationwide celebration of Brown's extensive works. It aims to encourage a wider, more diverse audience to visit, learn about and enjoy Brown's landscapes, of which there are more than 250 across England and a handful in Wales.
The Festival has been funded by a £911,100 grant from the Heritage Lottery Fund with the wider project worth around £1.7m.
The portrait of Brown chosen as the new face of the festival was painted by Richard Cosway, probably between 1770 and 1775, and is privately owned.
Gilly Drummond, who chairs the festival's project management board, said: "The Festival aims to celebrate Capability Brown's life, work, and the extraordinary legacy he left – both in terms of the rich array of sites attributed to him, and in his on-going influence on landscape design, which has been felt around the world.
"We are extremely grateful to the owner of the portrait, and to Bridgeman Images, for allowing it to be used."