Why did tecumseh, the shawnee chief, resort to an alliance with the british?

Shawnee Indian political leader and war chief Tecumseh (1768-1813) came of age amid the border warfare that ravaged the Ohio Valley in the late 18th century. He took part in a series of raids of Kentucky and Tennessee frontier settlements in the 1780s and emerged as a prominent chief by 1800. Tecumseh transformed his brother’s religious following into a political movement, leading to the foundation of the Prophetstown settlement in 1808. After Prophetstown was destroyed during the Battle of Tippecanoe, the Shawnee chief fought with pro-British forces in the War of 1812 until his death in the Battle of the Thames.