Lewis was born in Birmingham in 1897. He was educated at Marlborough College and in 1915 volunteered for the Northampton Regiment. After three weeks he found it was hard work and applied for a transfer to the RFC. They were full, and he was advised to obtain a private flying certificate. He asked his father for pounds 100, enrolled at Hendon and qualified that November on a Grahame White Boxkite; three weeks later so did his father.
After a basic course of instruction at Farnborough he was posted to Upavon, the RFC's Central Flying School and in April 1916 was awarded his pilot's brivet (wings). He then joined 32 Squadron and on 29 May, with only four and a half hours of flying in a DH2, flew with his squadron to France in a clapped-out plane while anxiously looking for a ship to land alongside in case his engine failed.
Although the youngest pilot of the squadron he was soon in action. Nearly 80 years later when I interviewed him for a book (There Shall be Wings: the RAF 1918 to the present day, 1993) he recalled an occasion on patrol in September 1916:
I was well above the rest when I spotted a two-seater Roland. I couldn't see his crosses until he passed right over, then I could see the observer looking over the side with his gun pointing straight at me. I went as white as a ghost, but for some reason he did not open fire.
He then described the major offensive south-west of Bapaune later that month when tanks went into action.
It was an incredible sight. We were going to win the war! All the infantry chaps were moving cheering the tanks. We saw no German aircraft. We dominated the skies - the infantry the ground. But it was all so short-lived. The casualties were terrible. I don't know how they stood it.
Lewis was to lose many friends from his squadron, but his most heartfelt loss was his elder brother Edmond, an inexperienced pilot who was shot down on his father's birthday after a single-handed fight with five enemy aircraft. It was a loss from which his father never recovered.
In September 1917 Gwilym Lewis was given command of an SE5 flight training pilots and then made a Flight Commander of 40 Squadron. Another Flight Commander was Mick Mannock, who named Lewis "Noisy" because he was so quiet.
In July 1918 Lewis was awarded the DFC. He was exhausted - and wise enough at 21 to realise this. Other pilots more experienced were not. On his last day in France at his farewell lunch, he recalled Mannock's taking the great Irish ace G.E.H. McElroy to one side and warning him not to follow the enemy down, because ground fire would get him. Six days later Mannock himself was killed by ground fire following down a two-seater. Five days after that McElroy was also shot down.
The final month of 1918 was spent as an Instructor at CFS, Upavon. Lewis decided against a career in the new RAF and was demobilised in 1919. He was 21. He was never to fly a plane again.
Lewis's qualities as both a pilot and a leader are possibly best exemplified by the fact that he never lost a novice pilot. When a new boy joined his squadron he would have him beside him, coax him and nurse him until he matured. (Sixty years later he received a note from one of those novice pilots: "With grateful thanks to Wing Commander `Noisy' Lewis DFC - my First World War Commander - and due to his splendid leadership I have been able to enjoy such a long and happy `after life'.")
After such an intense war in which command had come naturally to him, Lewis had some difficulty adjusting to a very junior position with the Lloyd's insurance brokers Sedgwick, Collins, especially as he was under the authority of men for whom he had little regard. However he soon joined up with old RFC pals also at Lloyd's and with them shared a cottage by the Thames at Wargrave. It was here that he met the 20-year-old Noel Coward who one Sunday read his first play, The Rat Trap, to Lewis and his friends as they languished in a punt.
In 1923 in bowler hat and rolled umbrella he went to America as the man from Lloyd's and on his return argued for a separate American Non-Marine Department, which upset a few people at Sedgwick's. When the crash came in 1929 he survived well although like everyone he had to face a reduction in salary. In 1925 he had married Christian Robertson and was happily married for 68 years. By 1939 he had built the American Non-Marine Department into the biggest department in Sedgwick, Collins.
During the Second World War Lewis was given the rank of Wing Commander and was part of the Cabinet War Room team. There he prepared detailed reports based on the previous 24 hours for the morning briefing. Ever eager to support the RAF, he gilded the lily once too often and Churchill good-naturedly returned the paper with the comment "No trench raids please!"
Throughout the war he retained contact with his firm and had copies of their cables sent to him. However during the time he was away there were many changes and in 1947, after more than 25 years' service, they decided to continue without him. Lewis then joined Arbon Langrish and on the death of the senior partner became chairman. He successfully built up the American side of the business before selling out to Clarkeson in 1965. However he maintained a lifelong interest in Lloyd's and was their oldest member.
Gwilym Hugh Lewis, aviator and insurance broker: born Birmingham 5 August 1897; DFC 1918; married 1925 Christian Robertson (died 1993; one son, two daughters, and one son deceased); died London 18 December 1996.