Isabella,Viscountess Molyneux, later Countess of Sefton

Isabella, Viscountess Molyneux, later Countess of Sefton, painted in 1769 and held at the Walker Art Gallery in Liverpool, is a full-length portrait from Gainsborough's mature Bath period that demonstrates his mastery of the large-format female portrait with landscape setting. The Molyneux family were Lancashire aristocracy with estates near Liverpool — giving the Walker Art Gallery's holding a regional resonance — and the commission for a full-length portrait at this scale was a significant one, of the type that competed directly with Reynolds's grand manner portraits at the Royal Academy. Gainsborough exhibited regularly at the Academy throughout the Bath years, and works like this Molyneux portrait established his reputation as Reynolds's equal in ambitious portraiture while distinguishing his more naturalistic approach. The Walker Art Gallery, Liverpool's principal public art collection, holds the portrait alongside other major British paintings that document the range of Georgian portraiture.

Gainsborough renders the viscountess with the warm palette and fluid brushwork of his middle period. The elegant pose and atmospheric landscape background create a portrait that balances formal grandeur with the natural grace that distinguished his approach from Reynolds's more intellectual style.