1920
In February The Instone Airline Limited started Hounslow/Paris services; the following month saw the closure of Hounslow and flights switched to Croydon, the new London Airport. New routes opened to Brussels and Amsterdam but the companies struggled without government support while across the Channel continental competitors received generous help.

March: Civil aviation moved from Hounslow Heath to Croydon, South London.

17 May: Air Transport and Travel together with KLM, inaugurated Croydon-Amsterdam service.

12 December: Air Transport and Travel ceased operations.

1921
28 February: Due to subsidised European competition, all British airlines ceased operations.

19 March: Temporary Government subsidy granted and British air services restarted; Handley Page Transport operated the first subsidised London-Paris service.

1922
1 January: Instone introduced uniforms for pilots and staff, believed to be the first airline service uniforms.

1 April: Government subsidy made permanent.

2 April: The Daimler Airway began operations from Croydon to Paris using ‘cabin boys’ on their aircraft.

1923
2 January: Civil Air Transport Subsidies Committee appointed under Sir Herbert Hambling “to consider the present working of cross-channel subsidies and to advise on the best method of subsidising air transport in the future.”

23 June: Handley Page Transport Ltd carried 79 passengers in one day.

1924
The government implemented the recommendations of the Hambling Committee about the future of British air services. Imperial Airways was incorporated on 31 March as the “chosen instrument” of the British government with the mission of developing British commercial air transport on an economic basis. The new airline was formed out of and took over the fleets of The Instone Airline Limited, The Daimler Airway, Handley Page Transport Limited and British Marine Air Navigation Co Ltd (operating a Southampton/Guernsey flying boat service).

Based at Croydon Airport, Imperial Airways would receive a government subsidy of £1m spread over ten years on the basis that they would be required to develop routes to the Empire – to South Africa, India and ultimately Australia – particularly for the carriage of mail. The Chairman was Rt Hon Sir Eric Geddes GCB, GBE. The initial fleet was three Handley Page W.8bs, two Supermarine Sea Eagles, one Vickers Vimy Commercial and seven DH34s. The primitive aircraft were used to develop the European routes to Paris, Zurich, Basle, Amsterdam, Hanover and Berlin.

Imperial Airways’ first flight was London Croydon to Paris Le Bourget, on 26 April, was by DH34 G-EBCX (Captain H.S. Robertson). It opened London (Croydon)-Brussels-Cologne daily services on 3 May, London (Croydon)-Amsterdam-Hanover-Berlin (in conjunction with Deutsche Aero-Lloyd AG) weekday services on 2 June and London (Croydon)-Paris-Basle-Zurich thrice-weekly services on 17 June.

1925
15 May: Imperial Airways’ Croydon-Amsterdam service became the first sector of England-Scandinavia through service. Imperial Airways operated London-Amsterdam and AB Aerotransport (Swedish Air Lines) worked Amsterdam-Copenhagen-Malmo; first Imperial Airways operation by DH34 G-EBBV.

1 October: First joint Air Ministry and Imperial Airways surveys of Egypt-India route completed.

16 November-13 March: Alan Cobham made Imperial Airways’ route survey flight from UK to Cape Town and back in the Armstrong Siddeley Jaguar-powered DH50J G-EBFO. The outward flight was London-Paris-Marseille-Pisa-Taranto-Athens-Sollum-Cairo-Luxor-Assuan-Wadi Halfa-Atbara-Khartoum-Malakal-Mongalla-Jinja-Kisumu-Tabora-Abercorn-Ndola-Broken Hill-Livingstone-Bulawayo-Pretoria-Johannesburg-Kimberley-Blomfontein-Cape Town. On his return Cobham was awarded the Air Force Cross for his services to aviation.

1926
4 May: First British Royal family member to fly with Imperial Airways – HRH The Prince of Wales, later King Edward VIII, flew Paris to London in Handley-Page W.10 G-EMBR City of Pretoria.

30 June: Alan Cobham left the Medway at Rochester in the DH50 G-EBFO on a commercial route survey to Melbourne, arriving on 15 August. He left Melbourne on 29 August and after completing 28,000 miles in 78 days with 320 hours flying the DH50 alighted on the Thames at Westminster on 1 October. Cobham was met on arrival by the Secretary of State for Air, Sir Samuel Hoare, and was subsequently knighted by HM King George V.

On 16 July Imperial Airways introduced the three-engined Armstrong Whitworth Argosy on the London Croydon-Paris Le Bourget route.

October: Agreement signed for Imperial Airways to operate UK-India route with maximum annual subsidy of £93,600.

27 December: Imperial Airways DH66 Hercules G-EBMX left Croydon for a survey flight to India; Karachi was reached on 6 January and Delhi on 8 January. The aircraft was named City of Delhi by Lady Irwin, wife of the Viceroy, on 10 January. The return flight left on 1 February 1927 and arrived at Heliopolis, Cairo on 7 February. Flying time Croydon-Delhi was 62 hours 27 minutes and Delhi-Heliopolis 32 hours 50 minutes.

1927
January: Imperial Airways operations opened Cairo-Baghdad-Basra sector of the Britain to India route.

On 1 May the luxury Silver Wing lunch service to Paris was introduced by Imperial Airways using the Armstrong Whitworth Argosy. With a comfortable recognisable airliner cabin, a steward, a four-course luncheon and a bar service, the flight took 2hrs 30mins and was a notable breakthrough in terms of comfort and service. In October, Imperial Airways introduced second class travel on the Paris route, using Handley Page aircraft without cabin service and a slower flying time.

Survey flights carried out to the Far East and South Africa laid the basis for the sought-after goal of regular links to the Empire. The initial link was established from Cairo to Baghdad in 1927 following pioneering work by the RAF; it was soon extended to Karachi and then Delhi.

6 October: Imperial Airways introduced the Supermarine Swan flying boat G-EBJY on the Southampton-Guernsey route. The route was closed in February 1929 when the Calcutta flying boats were transferred to the Mediterranean for the opening of the United Kingdom-India service.

1928
15 February: First Short S8 Calcutta flying boat G-EBVG built for Imperial Airways launched at Rochester.

2 May: The new passenger terminal at Croydon Airport, the Airport of London, was formally opened by Lady Maud Hoare; operations had begun earlier in the year.

15 June: Imperial Airways’ Argosy G-EBLF City of Glasgow (Captain Gordon Olley) with 18 passengers, from Croydon to Edinburgh Turnhouse in a race with the London and North Eastern Railways’ Flying Scotsman. The Argosy made two refuelling stops and completed the journey bout 15 minutes quicker than the train.

1 August: The Short Calcutta flying boat G-EBVG alighted on the Thames at Westminster and was moored there for three days for inspection by Members of Parliament, and others.