History
The R&A is the ruling authority of golf everywhere except the United States and Mexico where this responsibility rests with the United States Golf Association (USGA). It works in collaboration with national amateur and professional golf organisations in more than one hundred and ten countries. It also attempts to spread the game to new countries.
The R&A cooperates with the USGA in producing and regularly revising the "Rules of Golf", and the two bodies have issued the rules jointly since 1952. They also collaborate on the corresponding exegetic work, the "Decisions on the Rules of Golf". The R&A is also involved in formulating technical specifications for golfing equipment.
The R&A founded what are now the Official World Golf Rankings for male professionals in 1986 and the World Amateur Golf Rankings for male amateurs in 2007.

The R&A
The R&A organises 11 championships and international matches:
Apart from the Junior Open Championships all of these events are for men and boys. The Ladies Golf Union organises a similar range of events for women and girls, most notably the Women's British Open. The R&A is also involved in the organisation of the two World Amateur Team Championships - the Eisenhower Trophy for men and the Espirito Santo Trophy for women - through its role in the International Golf Federation.

The Open Championship: one of the four major championships in men's golf.
The Amateur Championship: which was one of the four major championships before the professional game became dominant and is still one of the most prestigious amateur tournaments in the world.
Boys Amateur Championship: for boys under the age of 18 at 00.00 hours on 1 January of the relevant year.
Boys Home Internationals: a team competition for boys from England, Scotland, Wales and all-Ireland.
Seniors Open Amateur Championship: for male amateurs aged 55 or over on the first day of competition.
British Mid-Amateur Championship: for amateurs aged 25 and over. This tournament was introduced to provide an elite competition for golfers who never turn professional as the main Amateur Championship is dominated by future professionals in their late teens and early twenties.
Senior British Open Championship: for men aged 50 and above. A major championship on the Champions Tour and the European Seniors Tour.
Walker Cup: a biennial men's amateur team competition contested by Great Britain & Ireland and the United States (co-organised with the United States Golf Association).
Junior Open Championships: for boys and girls under the age of 16 at 00.00 hours on 1 January of the relevant year.
St Andrews Trophy: a men's amateur team competition contested by Great Britain & Ireland and the Continent of Europe.
Jacques Leglise Trophy: a boys' amateur team competition contested by Great Britain & Ireland and the Continent of Europe. The present golf club

St Andrews Links
Old Course at St Andrews
British Golf Museum