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.

They most like influence us an there self

Could you give me some more details so i can you?