Founded by James Lansdowne Norton in England, the company's first motorcycle appeared in 1902 it used a French Clement engine in what was essentially a bicycle frame.

At the 1907 Isle of Man TT, H.Rem Fowler wins the twin cylinder class on a Norton, though not the one that still exists and is often claimed to be his TT bike. After the TT, H.Rem Fowler is said to have spoken of his "Unapproachable" Norton, thus coining the immortal phrase. 

In 1908 James "Pa" Norton designes his first own engine, a 633ccm side valve single, the "Model 1", later called the "Big4". The next one is the 3 1/2hp, later famous as the "16H". The firm's first commercial crisis  follows soon, due to Pa Norton's scant concern with commercial trivia. R.T.Shelley, of Vanderwell, saves Norton in 1924.