Early life 
Born Géza Áchim to " crusading Lutheran family" in the small village of Gyón near Dabas in modern Hungary, south of Budapest, after he learned at the high school in Békéscsaba. Gyóni adopted the name of his birthplace after dropping out of theological studies in the capital. His first collection of poetry, named simply Versek (Poems) was published in the same year, 1903. This marked a very low period in his life, in which Gyóni sought to free himself from his father's demands and even attempted suicide, before being transferred to an administrative course which led to a job in Budapest. In the city he was increasingly drawn to journalists and poets, contributing to the literary journal Nyugat and beginning a long rivalry with the contemporary leading poet of Hungary Endre Ady, who he criticized in his second collection, Szomorú szemmel (With sorrowful eyes) in 1909.
Military service 
In November 1907, Gyóni was called up to the Austro-Hungarian Army, and spent eighteen months working on railways lines, improving communications in case of war, an experience he did not enjoy, breeding a strong streak of pacifism in him. During this time and the following two years he continued working on his poetry in Budapest, until he was called up again in 1912 during the crisis caused by the Balkan Wars. His works in this period were later collected following his death, and posthumously published in 1917 as Élet szeretője (Lover of Life).
War Service 
At the outbreak of World War I, Gyóni was highly suspicious of his government's motives, but nonetheless seemed initially to enjoy the soldier's life, regularly writing poetry which was sent back home from the front for publication. This was the last collection he saw published and is considered by many to be his most interesting, as the optimism of early days gives way to pessimism following his experiences in the Siege of Przemyśl. This collection was named Lengyel mezőkön, tábortúz melett (By the campfire on Polish prairies). Home in Hungary, the politician Rákosi, knowing the poetic rivalry between Gyóni and Ady, who was now his main political rival too, used Gyóni's work as propaganda without permission. This greatly angered the poet, whose poetry took a depressive turn following his entrapment in the siege and the situation at home. One of his poems from this period, Csak egy éjszakára (Just for one night) became a prominent anti-war song which lasted in Hungary well beyond the end of the First World War.
Prisoner of War 
Captured in March 1915, Gyóni was permitted to remain with his younger brother Mihály Áchim, who had also been captured following the siege. They endured together the lengthy nine-month journey between POW receiving areas, travelling between Kiev, Moscow, Alatyr, Petropavlovsk, Omsk and finally to Krasnoyarsk in Siberia. It was in this camp that he learnt of the full actions of Jenó Rákosi, a politician who had been manipulating the poet's verse for propaganda value. Gyóni had only caught rumour before, and was enraged by what he learned.
He went on to write perhaps his finest poetry in the quiet and boredom he found there, producing the collections Levlek a kálváriáról és más költemények (Letters from Calvary and Other Poems) in 1916 which was published at home with manuscripts sent across the lines, and Rabságban (In Prison) which was posthumously published in 1919.
Gyóni died in the camp on his 33rd birthday, the result of his rapidly declining health and mental state following his brother's death from disease on the 8 June. He wrote a poem in captivity which represented his attitude to life entitled Magyar bárd sorsa (A Hungarian bard's fate).
A Hungarian bard's is my fate
To carry across the world
My bloodied, crusading Magyarhood
Like a pilgrim with a picture of Christ
- 1903 - Versek (Poems)
- 1909 - Szomorú szemmel (With sorrowful eyes)
- 1914 - Lengyel mezőkön, tábortűz melett (By the campfire on Polish prairies)
- 1916 - Levlek a kálváriáról és más költemények (Letters from Calvary and Other Poems)
- 1917 - Élet szeretője (Lover of Life) (posthumous)
- 1919 - Rabságban (In Prison) (posthumous)
- Cross, Tim, The Lost Voices of World War I, Bloomsbury Publishing, Great Britain: 1988. ISBN 0-7475-4276-7