1st Viscount, Air Chief Marshall Lord Hugh Trenchard, is one of the (fairly) major figures of British 20th Century history. Beginning as a pilot in the RFC, and working his way up to the equivalent of Colonel, he forged a name for himself throughout World War 1. Thus, when it was decided to combine the RFC and the RNAS to form a single combined service, Colonel Trenchard was chosen as the new leader of the Royal Air Force, making him the first ever Air Chief Marshall.
The RAF has changed a little over the years, but Lord Trenchard's foundations still show. Despite the fact that it looked like his work was to be undone when the Fleet Air Arm (the Navy's air force, for carrier based planes) was created, this has been repaired. In mid 2000, the two were recombined to form the Combined Arm 2000. Which does much the same thing as the RAF always used to do.
He was created 1st Viscount in recognition of his services to the country in the interwar period. The title of Viscount Trenchard still exists; the current holder is also called Hugh. By a strange quirk of fate, his son has EXACTLY the same names as me.