Once a prominent vacation world for the Hutts, Teth suffered an economic crisis when the Galactic Republic began to crack down upon the criminals housed on-planet. Prior to the Clone Wars, Jedi Master Plo Koon helped local constable Janu Godalhi capture pirates as part of the Republic crackdown, futher driving the Hutts out.
The Clone warsEdit
During the Clone Wars, the planet was home to Confederate agents who'd kidnapped Rotta, son of Jabba Desilijic Tiure, concealing themselves within a B'omarr Monastery-turned-fortress on a mesa. The monastery soon found itself the site of a large battle between Republic and Separatist forces. The battle raged up the mesa's cliff side, in which the Republic's primary weapon were standard AT-TE Walkers, which were used to climb up to the fortress. Upon reaching the top, Anakin Skywalker and Ahsoka Tano recovered the missing Huttlet. Later, Skywalker and Tano found the Twilight on an adjacent cliff, and used it to transport Rotta back to his father on Tatooine.
Later in the war, Ziro the Hutt visited his father's hidden grave, located on the planet. He used the site to hide a holo-journal containing information about the Hutt Grand Council's illegal dealings. As he recovered the journal, Ziro was betrayed by his girlfriend Sy Snootles, who shot him dead and took the journal to Jabba, her employer.
Under the new orderEdit
Having ridden itself from the criminal gangs and mercenaries due to the efforts of its local constabulary and the Republic, Teth became the capital of the Baxel sector under the rise of the Galactic Empire, and control was given to Moff Sarn Shild. The Empire built the capital Peroon, a naval base and small shipyard, and made the planet an agriworld. Teth gave the Empire nominal control of Hutt Space and created a bulwark against the Hutts' schemes. 
The Hutts, however, reacted with investments, threats and bribery and created a criminal underground on the planet, exploiting a portion of the harvest income.
Galactic civil warEdit
Moff Shild later used the planet as the marshaling point for his fleet before he launched his attack on Nar Shaddaa in 4 BBY.
It was also the location of an early Rebel cell. It was considered a significant investment, as the Corellian Rebels were willing to risk sending the valued commander Bria Tharen across the galaxy to make contact with them. The Tethan Rebels declined to join an outright alliance, but were willing to increase their attacks on Imperial targets like supply dumps and ships coming to and from the Corporate Sector and help funnel the proceeds to their Core-ward brethren.
After the Empire's fall, the Hutts returned to the planet, which by then had been made richer by the Empire's influence.