Short answers, pulled from the story.
Hamish Hamilton Limited was founded in 1931 by Jamie Hamilton, a half-Scottish, half-American publisher. The name Hamish is the Gaelic vocative form of Seumas, meaning James, which was also Hamilton's given name.
Hamish Hamilton published Raymond Chandler, J. D. Salinger, James Thurber, E. B. White, and Truman Capote in the United Kingdom. Many of these authors were personal friends and acquaintances of Jamie Hamilton.
Hamish Hamilton is now an imprint of Penguin Random House. Jamie Hamilton sold the firm to the Thomson Organisation in 1965; Thomson resold it to Penguin Books in 1986, and Penguin merged with Random House in 2013.
Five Dials was an online literary magazine founded by Hamish Hamilton in 2008. It ran for sixteen years before closing, with its full archive remaining available after closure.
Recent Hamish Hamilton authors include Zadie Smith, W. G. Sebald, Bernardine Evaristo, Alain de Botton, Paul Theroux, John Updike, and R. K. Narayan. The imprint aims to publish innovative literary fiction and non-fiction from around the world.
Hamish Hamilton was established in Bloomsbury, the literary district of London. The location placed the firm at the heart of the British publishing world during the mid-twentieth century.