Sienna Tiggy Guillory (born 16 March 1975) is an English actress, and a former model. She is well known for playing the title role in the TV miniseries, Helen of Troy
. She is also well known for her portrayal of Jill Valentine in the science fiction action horror film Resident Evil: Apocalypse
and as elf princess Arya Dröttningu in fantasy-adventure film, Eragon
, based on the novel by Christopher Paolini. She resumed her role as Jill Valentine in the action horror film Resident Evil: Afterlife in 2010, and continues to resume her role in Resident Evil: Retribution
scheduled for release September 14, 2012.