Which is the oldest tournament of the men's four major golf championships?

The Open Championship, often referred to as The Open or the British Open, is the oldest of the four major championships in professional golf. Held in the United Kingdom, it is administered by The R&A and is the only major outside the United States. The Open is currently the third major of the year, between the U.S. Open and the PGA Championship, and is played in mid-July.

The Open was first played on 17 October 1860 at Prestwick Golf Club in Scotland. The inaugural tournament was restricted to professionals and attracted a field of eight golfers who played three rounds of Prestwick's twelve-hole course in a single day. Willie Park Sr. won with a score of 174, beating Old Tom Morris, by two strokes. The following year the tournament was opened to amateurs; eight of them joined ten professionals in the field.