Winning the four majors, the most important tournaments for golf professionals, in one year. (You can find a further overview of all important golf tournaments here)
Currently the most important tournaments are the Masters Tournament in the USA (Augusta, Georgia), the Open Championship (Great Britain), the US Open and the PGA Championship (both in the USA).
A look at the history
Originally there was only the Open Championship. In 1885 the Amateur Championship (British Amateur) was held for the first time, in 1895 the US Open and the US Amateur Championship were added. From that time on, one could speak of a Grand Slamaus of these four tournaments, but nothing is not animated.
The journalist O. B. Keeler made the term popular in 1930. He called the first – and so far the only – winner Bobby Jones that.
Changes in amateur sports
With the introduction of the Masters in 1934 and the declining importance of amateur sport, the definition of major tournaments and thus also of the Grand Slam shifted to the four professional tournaments of today.
Three Majors in one calendar year was first won by Ben Hogan in 1953. However, he was unable to participate in the PGA Championship, which was held at the same time as the Open Championship.
All four majors in consecutive order – albeit spread over two calendar years – were won by Tiger Woods. In 2000 he won the US Open, the Open Championship and the PGA Championship. In 2001 he won the Masters. The fact that Woods won all four Majors in unbroken succession is also known as the Tiger Slam.