I couldn’t find any info about this coin. It appears to commemorate a Millenia since the birth of st Stephen in 969.
Hungary did issue two commemorative coins on that occasion: 50 and 100 forint, silver. They came out and are dated 1972. Not sure when Stephen was actually born - some sources say 969, others 975, so 1972 is a good middle of the road approach. (By the way, the pengő had been replaced by the forint in 1946.) The depicted crown, by the way, was still in the US when that medal was issued - it was not returned until 1978. So maybe that piece was not made in Hungary? Just a guess. Edit - What I find a little confusing is that, among the Latin text, you also have the word "committee" which is neither Latin nor Hungarian but English. Could "HUNG·NAT·" be English too - as in "Hungarian National Committee"? Christian Christian