Complex sentence: Shortly after the seige of Rhen Var, the Republic detected unusual activity on Raxus Prime, and sent a strike force led by Jedi Knights Anakin Skywalker and Obi-Wan Kenobi to investigate the activity.
Split into simpler sentences: Shortly after the seige of Rhen Var, the republic had scanned some unusual activity on Raxus Prime. The Republic decided to send a strike force led by Anakin Skywalker and Obi-Wan Kenobi to check out the activity.