Sergeant Major Christopher Demosthenous was born in Queens, NY and enlisted in the Marine Corps on 9 September 1996. After completing Recruit Training at MCRD Parris Island, SC, he reported to the School of Infantry East for Marine Combat Training (MCT). Upon completion of MCT, he reported to Fort Sill, OK for his Military Occupational Specialty at the Field Artillery School to become a Cannon Crewman. Once his training was complete, he was assigned to 3rd Battalion 12th Marines in Okinawa, Japan. During this period, he was promoted to Lance Corporal.
In January of 1998 Lance Corporal Demosthenous received orders to Lima Battery 3rd Battalion 11th Marines, in 29 Palms, CA. In April of 1998 he was promoted to Corporal and assigned the billet of Section Chief. In July of 1998 and September 1999, he deployed with Lima Battery on a UDP to Okinawa, Japan.
In June 2000 Corporal Demosthenous received orders to attend Marine Security Guard School in Quantico, VA where he was promoted to the rank of Sergeant in July 2000. After completion of Marine Security Guard School, he was assigned to Lusaka, Zambia as his first post, and was re-assigned to Ottawa, Canada for his second post.
In March of 2003 Sergeant Demosthenous received orders to Lima Battery 3rd Battalion 11th Marines in 29 Palms, CA. He was promoted to Staff Sergeant in February 2004, and was then assigned to the billet of Platoon Sergeant for Guns Platoon. In March 2004 he deployed to Ar Ramadi, Iraq in support of Operation Iraqi Freedom. In September 2005 he deployed on a UDP to Okinawa, Japan, then in September 2006 he deployed to Rawah, Iraq, where he was attached to 2nd LAR and served as Platoon Commander and Quick Reaction Force Team Commander.
In October 2007 Staff Sergeant Demosthenous received orders to attend Drill Instructor School in Parris Island, SC. After completion of Drill Instructor School, he received orders to attend Marine Combat Instructor of Water Survival School (MCIWS). After completion of MCIWS he was assigned to Golf Company, 2nd Recruit Training Battalion where he did eight training cycles and held the billets of drill instructor, senior drill instructor and series chief drill instructor. In July 2009 he was promoted to the rank of Gunnery Sergeant.
In November 2010 Gunnery Sergeant Demosthenous received orders to 1st Battalion 11th Marines in Camp Pendleton, CA where he was assigned the billet of Battery Gunnery Sergeant for India Battery 1st Battalion 11th Marines. In May 2012 he deployed with the unit on the 31st MEU.
In January 2013 he was selected to the rank of First Sergeant and received orders to MCRD San Diego, CA. While at MCRD San Diego he held the billet of Company First Sergeant for Charlie Company, 1st Recruit Training Battalion for eight training cycles until June 2015.
In June 2015 First Sergeant Demosthenous received orders to Marine Corps Base Quantico, VA, where he held the billet of Company First Sergeant for Tenant Activities Company and two augment cycles with Officer Candidates School.
In May 2018 he was frocked to the rank of Sergeant Major and reported to Chicopee, Ma where he held the billet of Site Sergeant Major for Site Support Chicopee, MACG-48 until May 2021.
In May 2021 Sergeant Major Demosthenous reported to Camp Lejeune, N.C. where he held the billet of Battalion Sergeant Major for II MEF Support Battalion.
In March of 2023 Sergeant Major Demosthenous reported to Camp Pendleton, CA where he currently holds the billet of Regimental Sergeant Major for 11th Marine Regiment.
Sergeant Major Demosthenous' personal awards include the Meritorious Service Medal with two gold stars in lieu of third award, Navy and Marine Corps Commendation Medal with Combat Distinguishing Device, and two gold stars in lieu of fourth award, Navy and Marine Corps Achievement Medal, and the Combat Action Ribbon.