This is copied from an official Source at the Isle of Man :
The Isle of Man became a Viking outpost/kingdom from circa AD 700 to AD 900. The Norse Kingdom of Mann and the Isles was created by Godred Crovan in 1079. Norway's King Magnus VI ceded the isles to Scotland in 1266, as dictated in the Treaty of Perth. The Isle of Man came under English control in the 14th century and to the British Crown in 1765.
The Island arguably has the oldest continuous parliament in the world, the Tynwald, nominally founded in 979 AD (both the Icelandic parliament and the Faroese parliament are older, but they were abolished between 1800 - 1845, and 1816 - 1852 respectively). The annual ceremonial meeting at Tynwald Hill, on Tynwald Day in July, continues the celebration of the Island's national day. The main purpose of the occasion is to read the titles and to give a brief description of the new laws which have been enacted by the Tynwald Court during the previous year.
For centuries, the Island's symbol has been the ancient Triskelion: three bent legs, each with a spur, joined at the thigh. The Triskelion does not appear to have an official definition — Government publications, currency, flags, the tourist authority and others all use different variants. Most, but not all, preserve rotational symmetry. Some run clockwise, others anticlockwise. Some have the uppermost thigh at 12:00, others at 11:30 or 10:00, etc. Some have the knee bent at 90°, some at 60°, some at closer to 120°. Also the degree of ornamentation of the leg wear and spur vary considerably.
The three legs relate directly to the island's motto — Quocunque Jeceris Stabit, which translates to Whithersoever you throw it, it will stand. Interpretations of the motto often stress stability and robustness in the Manx character. Many schools on the island have adapted the motto to promote perseverance and hard work.
Variations on the Triskelion are still in use on the coats of arms belonging to the different branches of the ancient Norwegian noble family that ruled Mann up until the 13th century. This particular version belongs to the Skancke branch of the Skanke family. The name stems from skank, the Norwegian version of the word shank. The Norse royal family of Man stayed on the island for some years after the death of Magnus III and the beginning of Scottish rule. The family's emigration only came after the a final attempt on the Manx' part at restoring the old Sudreyar dynasty in the 1275 uprising against the Scots. This revolt failed disastrously, ending in the deaths of hundreds of rebels, including the last Norse King of Man, Godred Magnusson when the Manx suffered defeat in the decisive Battle of Ronaldsway, near Castletown. When the Norse-Manx royals arrived in Norway they took service as nobles of the Norwegian king, quickly becoming knights, landlords, and clergy under the Norwegian Crown.