From the English Wikipedia page [1].

The National Archives of Hungary (in Hungarian: Magyar Országos Levéltár) were created in 1756. They were first located in Bratislava. In 1784, they were transferred to Buda (now part of Budapest).

More information on the Hungarian [2] and German [3] Wikipedia pages - the latter has a list of directors.

The website, in Hungarian, is [4]

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