The Royal and Ancient Golf Club became the sole organiser of The Open in 1920.
The change came when the championship resumed after the First World War. The previous Open had been held in 1914; championships were not staged during the war, and the 1919 event was also cancelled. The 1920 revival was played at Royal Cinque Ports Golf Club in Deal, England, and marked the beginning of the Royal and Ancient's sole-organiser role.
The move helped centralise responsibility for a tournament that had grown beyond its early Prestwick origins. The Open's venues continued to rotate among leading links courses in Scotland and England, but organisational control was no longer shared in the earlier way.
This date is easy to confuse with later milestones. In 1926, the tournament standardised its three-day format, including qualifying and a cut. The year 1892 belongs to an earlier expansion of the venue rotation, while 1946 marks the post-Second World War return of the championship—not the organisational change.