The Senate War Rally was an event that occurred during the Clone Wars, which was done to promote the war effort. It was held by the Galactic Senate of the Republic, led by Supreme Chancellor Palpatine.
Hours before the rally, Anakin Skywalker arrived at Palpatine's Statue Garden to inform the Supreme Chancellor that he would not be able to make it to the event, as he and a Jedi task force had been dispatched to track down the Sith Lord Darth Maul.