The Attack on SkyWind III occurred during the Clone Wars. Separatists targeted Republic politicians and diplomats to gain an advantage over the Republic. In a surprise attack the Separatist destroyer Starshot disabled the Alderaanian diplomatic vessel SkyWind III. The Separatists boarded the ship with droids and commandos, hoping to capture Ambassador Lerron, one of Alderaan's accomplished diplomats.
Sources
Repel Boarders: Part 1 on Wizards.com (original site is defunct)
Repel Boarders: Part 2 on Wizards.com (original site is defunct)