The Ox Mountains form a half-circle around Sligo, the town in the North-West of Ireland, where Yeats grew up. He is the best-known Irish painter of the 20th century, himself the son of the portrait painter John Butler Yeats, and brother of the celebrated poet William Butler Yeats. As a painter he was drawn to the area's continually shifting light and shade, and the changes in quality of atmosphere, which he captured with extremely loose brushwork. As a fervent Irish nationalist the landscape, history and mythology of Ireland were emotive sources of inspiration for his art, and the Yeats brothers thought of the area as the 'Land of Heart's Desire'. The indigo blue of the hills is typical of his palette in the 1940s. His early work as a painter was influenced by the French Impressionist pictures that he had seen in the collection of the Irish dealer Hugh Lane, however, from the mid-1920s he developed a highly personal Expressionist technique, which bears a similarity to the work of Oskar Kokoschka, who became a great friend in the last decade of Yeat's life.