The rotation of the six courses was reinstated after the First World War with Royal Cinque Ports hosting the first post-war Open in 1920. It had been chosen as the venue for the cancelled 1915 Open. In 1923 Troon was used instead of Muirfield when "some doubts exists as to the Honourable Company of Edinburgh Golfers being desirous of their course being used for the event". Muirfield returned as the venue in 1929. Serious overcrowding problems at Prestwick in 1925 meant that the course was never again used for the Open and was replaced by Carnoustie as the third Scottish course. While Royal St George's and Royal Liverpool continued to be used at six-year intervals the third English course varied. After Royal Cinque Ports in 1920, Royal Lytham was used in 1926 and then Prince's in 1932. Royal Cinque Ports was intended as the venue in 1938 but in February of that year abnormal high tides caused severe flooding to the course leaving it like "an inland sea several feet deep" and the venue was switched to Royal St George's. Birkdale was chosen as the venue for 1940, although the event was cancelled because of the Second World War.