In 1944, Orwell began work which "encapsulate[d] the thesis at the heart of his... novel", which explored the consequences of dividing the world up into zones of influence, as conjured by the recent Tehran Conference. Three years later, he wrote most of the actual book on the Scottish island of Jura from 1947 to 1948 despite being seriously ill with tuberculosis.[12][13] On 4 December 1948, he sent the final manuscript to the publisher Secker and Warburg, and Nineteen Eighty-Four was published on 8 June 1949.[14][15]