Urumi

The urumi is a flexible, whip-like sword native to Kerala in southwestern India, its long thin blade of spring steel able to be worn coiled around the waist like a belt and concealed until drawn and snapped straight for use, a construction unlike almost any other bladed weapon in the world. Its origins trace back to the ancient Sangam period of South Indian history, and the weapon became closely associated with the systematized Kalaripayattu martial arts tradition of medieval Kerala, in which it is taught as one of the most advanced and dangerous weapons, requiring years of training before a practitioner is considered safe to wield it. Because a mishandled stroke could as easily injure the wielder as an opponent, given the blade's tendency to whip back unpredictably, the urumi holds a reputation within Indian martial tradition as one of the most difficult weapons to master, prized as much for its concealability and surprise value in personal combat as for its usefulness in a formal battlefield line.