Chris Kyle enlisted in the U.S. Navy in 1999, overcoming a severe arm injury that initially hindered his military aspirations14. He completed Basic Underwater Demolition/SEAL (BUD/S) training with Class 233 in 2001 and was subsequently assigned to SEAL Team 31. Kyle served four tours in Iraq from 2003 to 2009, participating in major battles such as Fallujah, Ramadi, and Sadr City14. His exceptional marksmanship earned him the reputation of being the most lethal sniper in U.S. military history, with 160 confirmed kills12. Iraqi insurgents, who feared his deadly accuracy, nicknamed him "al-Shaitan" (the Devil) and placed a bounty on his head34. Kyle's valor and effectiveness in combat were recognized with numerous awards, including one Silver Star and three Bronze Stars with Valor2.

Chris Kyle served four tours of duty in Iraq between 2003 and 2009, participating in every major campaign of the war14. His first confirmed kill as a sniper came in March 2003 during the initial invasion, when he shot a woman carrying a grenade who was approaching U.S. Marines13. Throughout his deployments, Kyle earned a reputation for exceptional marksmanship and bravery. He served in Fallujah in 2004, Ramadi in 2006, and Baghdad's Sadr City in 200814. Kyle's longest confirmed kill was made from an estimated distance of 2,100 yards (1.2 miles) in Sadr City, where he shot an insurgent armed with a rocket launcher1. By the end of his service, Kyle had accumulated 160 confirmed kills, though he estimated the actual number could be as high as 2553. His lethal efficiency earned him the nickname "al-Shaitan" (the Devil) among enemy fighters, who placed a bounty on his head2.

After retiring from the Navy SEALs in 2009 to focus on his family, Chris Kyle authored the bestselling autobiography "American Sniper" in 2012, which detailed his military experiences and became a national sensation2. He founded Craft International, a tactical training company that provided specialized training to military and law enforcement personnel2. Kyle also dedicated himself to helping veterans, particularly those suffering from PTSD, through initiatives like the FITCO Cares Foundation, which provided exercise equipment and support to veterans2. His efforts to assist fellow veterans tragically led to his death in 2013 when he was killed by a troubled veteran he was trying to help at a Texas shooting range14.

On February 2, 2013, Chris Kyle and his friend Chad Littlefield were shot and killed at a shooting range in Erath County, Texas, by Eddie Ray Routh, a former Marine suffering from PTSD and other mental health issues3. Kyle and Littlefield had taken Routh to the range to help him cope with his condition, but Routh turned on them, shooting Kyle six times and Littlefield seven times3. Routh fled the scene in Kyle's truck and was later arrested at his sister's home after confessing to the murders13. During the trial, Routh's defense argued he was insane, but the prosecution countered that he was aware of his actions. The jury found Routh guilty of murder, and he was sentenced to life in prison without parole24.