Why did it start?
     
 

Motor racing first came to the Isle of Man in 1904 when the Gordon Bennett car trials were held. In England it was impossible to close the public roads for racing, so a proposal was put to the Isle of Man government. The government brought in new legislation to enable the closing of public roads for racing, and the Isle of Man was ready to take up the mantle of The Road Racing Capital of the World.

In 1905, the Auto-Cycle Club decided to send a team of riders to compete in the International Cup races in France. There was no suitable venue to hold the races on mainland Britain, but a precedent had been set for the Isle of Man in 1904 when Julian Orde, Secretary of the RAC, had persuaded his uncle, Lord Raglan, then Governor of the Isle of Man, to allow car racing on the island. The cars used a 52-mile course, starting from Quarter Bridge, down south to Castletown. Turning right at Castletown Bridge (on the Southern 100 course), they climbed the Ballamhoda Straight, through Foxdale to Ballacraine; it followed the current TT course to Ballaugh Bridge, where it turned left to Ballaugh Cronk, through Sandygate (on part of the Andreas Racing Club's Jurby Road circuit) to Ramsey, then across Snaefell and back to Douglas. After a few practice runs, it was found that the course was far too demanding for the single-geared motorcycles, and, following consultations with the competitors, an abbreviated 25-mile version of the car course was run. At Ballacraine, the competitors turned right and returned to Douglas, following the TT course, but in reverse. The event was over 5 laps, 125 miles. Eighteen entries were received, eleven arrived on the Island, four succumbed to either machine failure or rider error in practice and the trial were won by J. S. Campbell (6 hp Ariel-J.A.P.), second was Harry Collier (6 hp Matchless-J.A.P.) and third was Charles Franklin (6 hp J.A.P.). Campbell never returned to compete in the TT, but both Collier and Franklin were to record TT victories later in the decade. Collier went on to finish third in the 1906 Intenational Cup race in Austria, but the event was marred by claims of 'outside assistance' being given to the local Puch riders. Sir Arthur Conan Doyle, author of the Sherlock Holmes stories, was the entrant of Tom Silver in the 1905 race.

Motorcycle road racing first came to the Isle of Man in 1907 when the first TT races where held on the Short Course. This was a triangular course with the start at St John's. The riders proceeded along the course to Ballacraine before turning left and following the current TT course through to Kirk Michael. At Douglas Road Corner in Kirk Michael, the Short Course left the current TT course and followed the coast road to Peel, before turning left again and heading back to St John's.