The clash on Merson, known as the Battle of Merson, which occurred during the Clone Wars, involved the deployment of Galactic Republic troops to the planet. These forces, under the command of Jedi Master Ronhar Kim, his apprentice Tap-Nar-Pal, and Captain Gilad Pellaeon, were dispatched for combat.
The strength of the opposition on the planet was severely underestimated by Republic Intelligence, by a factor of five, leading to their defeat. The Separatists were prepared for the incoming attack thanks to a warning from Darth Sidious to Count Dooku, informing him of the Republic's imminent arrival. Consequently, the Merson pirate forces present were bolstered with CIS droids and other resources.
Captain Pellaeon ordered a retreat when additional CIS units arrived, resulting in Master Ronhar Kim, his Padawan, and the remaining soldiers being left to perish. Kim's Padawan attempted to provide aerial support to his master by performing a strafing run, but he was taken down by B2 super battle droids.
The demise of Jedi Master Kim meant that his scheme to evaluate members of the Galactic Senate for elevated midi-chlorian levels was never realized. Consequently, Chancellor Palpatine's concealed identity as Darth Sidious was preserved.