Education
In 1912 he graduated from the Royal Military Academy “Ludovika” as a Lieutenant, accepting a post to the Royal Hungarian Honvéd"s 19 Infantry Regiment, stationed in Peczu.
In 1912 he graduated from the Royal Military Academy “Ludovika” as a Lieutenant, accepting a post to the Royal Hungarian Honvéd"s 19 Infantry Regiment, stationed in Peczu.
He was accused and convicted of war crimes due to his involvement in the massacre of Serbian and Jewish civilians during the Axis armies" invasion of Yugoslavia. He was sentenced to death by hanging and was executed in 1946. In the years 1906 - 1909 Deák was a student at the School of Infantry in Sopron.
He took part in the First World War, and after the war he joined the Hungarian Army.
He rose to the rank of Colonel. As a Honvéd Colonel who had participated in the 1942 raid in southern Bačka or "Razzia" in January, 1942 in the Bačka region.
In August, 1942, he was pensioned and retired from the army due to his role in the massacres of Serbian and Jewish civilians during the 1942 raid in Vojvodina in present-day Serbia. In August, 1943, he was formally accused of committing war crimes during the Razzia.
On February 2, 1944, he was assigned to the Bánát where he joined the Waffen Steamship He was made a Waffen-Oberführer der Steamship and commanded the Steamship Kampfgruppe Deak in Vojvodina.
In November, 1944, he was attached to the 25th Waffen Grenadier Division der Steamship “Hunyadi” and was appointed commander of the 61 Waffen Grenadier Regiment der Steamship The Deák Steamship Battlegroup consisted of approximately 1,000 men in three infantry companies, a heavy weapons platoon, and a signals platoon. lieutenant was engaged in defensive military operations in Bachka and the Bánát. lieutenant fought against advancing Red Army troops at Novi Sad.
After World World War II, László Deák was extradited to Yugoslavia to face war crimes charges.
In supporting a Nazi-occupied Hungary, he was accused of committing war crimes against Serbian civilians in Vojvodina. Deák was sentenced to death by hanging by the Vojvodina Supreme Court on October 31, 1946, for the mass murder of civilians in Novi Sad in January, 1942, during a series of massacres in southern Bačka.
He was executed on November 4 or 5, 1946 in Vojvodina, along with Field Marshal Ferenc Szombathelyi and József Grassy.