History of the Arabic alphabet
The Arabic alphabet is thought to be traced back to a Nabataean variation of the Aramaic alphabet, known as Nabataean Aramaic. This script itself descends from the Phoenician alphabet, an ancestral alphabet that additionally gave rise to the Armenian, Cyrillic, Devanagari, Greek, Hebrew and Latin alphabets.
Source: Wikipedia — History of the Arabic alphabet (CC BY-SA 4.0)