"Golf in the early days as it became organised was very much the preserve of the wealthier classes, professional and military men and the landed genry who not only had the time to play but the wherewithal to afford the cost of early equipment, particularly feather golf balls which were incredibly expensive. The first golf club members were therefore gentlemen of substance and it was not until the arrival of the much less expensive gutta percha ball in 1848 that the game had a chance to expand into the wider community. As it did so the demand for more courses and for teachers became imperative, and golf began to see the emergence of the professional. These men who made golf their business arrived from the ranks of the caddies, who had previously carried the clubs of their gentlemen employers, and from the ball makers like the first professional, Allan Robertson, who kept the gentlemen players supplied with their expensive feather balls. Golf was able to cross the barriers of class as in no other walk of life. Great matches were played between sides composed of gentlemen players and professionals. Allan Robertson and Old Tom Morris and Willie and Jamie Dunn of Musselburgh often did battle with huge sums of money resting on the outcome. Large crowds used to follow the matches and betting was often heavy on the result. As the game expanded quickly in the second half of the nineteenth century, money matches, and eventually tournaments, were eventually held for professional players only. The first of consequence was the Open Championship of 1860, restricted to professional players with caddies who had to be supervised by gentlemen 'markers' to ensure that the rules of golf were strictly adhered to. When the gentlemen players were allowed to play in the event the following years, the professionals were still required to have markers, but the gentlemen players were trusted entirely to conduct themselves appropriately on the links."