Lieutenant Colonel Ēriks Keisters started his service in the National Armed Forces (NAF) in 2000. He has served as the Commander of 1st Mechanized Infantry Battalion Platoon at the NAF Mechanized Infantry Brigade, as a Company Commander, Head of the Planning Division and the Deputy Commander of the Battalion. Continued service as a senior officer of the Land Forces Mechanised Infantry Brigade Planning Department and later has been the Commander of the newly established 3rd Infantry Battalion.  Ēriks Keisters has participated in several international operations in Iraq and Afghanistan during the service, commanding an infantry platoon and a company and serving as a planning officer for the manoeuvre group. Lieutenant Colonel Ēriks Keisters has acquired military education by graduating from the Swedish Military Academy in Halmstad, has accomplished a course of the U.S. Army Manoeuvre Centre Commander with honours, as well as a course of Joint Command and General Staff at the Baltic Defence College (also with honours). Ēriks Keisters has completed the Army Command and Staff Course at General Jonas Žemaitis Military Academy of Lithuania as well as the Joint Command and General Staff Course at the BALDEFCOL. In addition to military education, Lieutenant Colonel Ēriks Keisters has graduated from several higher education institutions in Latvia, acquiring a first-level higher education at the College of Business Management (“bronze diploma”), a Bachelor of Management Sciences and a Master's degree (with honours) at the EKA University of Applied Studies, as well as a master's degree in “Military Leadership and Security” at the National Defence Academy of Latvia. For his courage and heroism in the international operation in Iraq, Ēriks Keisters is awarded with the Order of Viesturs and appointed as the Knight of the Order of Viesturs.