The ancient Hungarians, or Magyars as they call themselves, had a distinctive writing system called rovásírás (rovás for short), or Old Hungarian script in scholarly circles. This script is also called "Hungarian runes" due to the angular shape of its letters, but it is not related in any way to Germanic Futhark. Instead it is most likely related to Turkic Runes employed by Turkic tribes in southern Siberia, which the Magyars encountered and interacted with in their migration from Central Asia to Europe.
The oldest rune-shaped inscription in Hungary dates from the 9th and 10th centuries CE, but these earliest texts are poorly understood and maybe even not in the Hungarian language but perhaps in an unidentified Turkic dialect. The first mention of the Old Hungarian script occurred in the late 13th century CE in a Latin chronicle of the Hungarians written by Simon de Kéza which mentions the rovás of the Székelys, a subgroup of the Magyar that inhabited Transylvania instead of the Carpathian basin. The earliest Old Hungarian abecedary, a list of all letters in an alphabet, appears in a printed book from the palace library of the city of Nikolsburg and dates to 1483.
The following is the Old Hungarian alphabet as it appears in the Nikolsburg book.
Note that red texts are the phonetic values of the letters, whereas blue texts are the modern Hungarian notation for these sounds.
Latin became the official language of Hungary when the Kingdom of Hungary was founded in the year 1000 CE, but the Old Hungarian script continued to be used in popular context for the next 800 years. However, the 19th century saw the modern Roman-based Hungarian orthography becoming widespread in all segments of Hungarian society, and the ancient rovásírás fell into complete disuse.