Sienna Tiggy Guillory (born 16 March 1975) is an English actress, and former model. She is known for playing the title role in the TV miniseries, Helen of Troy, as elf princess Arya Drttningu in fantasy-adventure film, Eragon, and for her portrayal of Jill Valentine in the science fiction action horror film Resident Evil: Apocalypse. She resumed her role as Jill Valentine for a cameo appearance in the 2010 action-horror film Resident Evil: Afterlife, and in Resident Evil: Retribution, released on 14 September 2012.