I told a lie, I must confess, with my earliest mention, in this thread, of Franz Liszt.
The poem, eventually altered to "Isten veled," was the first Hungarian-language text set to music by Liszt. However, it was not the last, I apologize for the error.
When Liszt was an old man, no longer performing, mostly teaching, and composing a little, he set to music two texts by none other than Sandor Petofi, and highly patriotic texts they are, too.
By then the battle in which Petofi, amongst the soldiers, disappeared, never to be seen again dead or alive, was long past; and Petofi, posthumously, was celebrated wherever Hungarian was spoken. Petrichevich-Horväth, on the other hand, was also long dead, and largely forgotten.