Lieutenant General Themistoklis Grymbiris was born in 1965 in Piraeus. He was admitted to the Hellenic Army Academy in 1982 and graduated in 1986 having received his commission as Artillery 2nd Lieutenant.
He attended all the schools stipulated for Artillery, as well as the Army War College and the National Defence College.
Throughout his career he has served in Artillery Units, as an instructor in the Artillery School, as a staff officer in the Staff of 96 Higher National Guard Battalions Command (Chios) and in the National Guard General Staff.
He has also served as Commander at the 147 National Guard Battalion (Chios) and the 95 National Guard Unit (Rhodes).
He has served as a staff officer at the HAGS Artillery Directorate, as the aide-de-camp of the Army for His Excellency the President of the Hellenic Republic Mr. Karolos Papoulias (2008-2011), as well as Defence Attaché of the Embassy of Greece in Berlin with concurrent accreditation for the Czech Republic, Poland, Austria and Sweden (2011-2014).
In 2015 he was promoted to the rank of senior Officer (Brigadier General) and was assigned as Commander of the 96 Higher National Guard Battalions Command (2015-2016).
In 2016 he was assigned as Director of the HAGS Operations Directorate (2016-2018).
In 2018 he was promoted to Major General and was assigned as the Director of A’ Branch of the Higher Army Support Military Command (2018-2019).
In 2019 he was assigned as Chief of Staff (2019-2020) at the Higher Army Support Military Command.
On 19th March 2020 he was assigned as Commander of the Hellenic Army Academy.
In 2021 he was promoted to Lieutenant General and on the 10th of March 2021 he was assigned as Commander at the National Defence College.
He has been awarded all the stipulated decorations, medals and commendations.
He speaks English and at a working level German.
He is married and has a son.