When we speak about an “alphabet” we indicate a series of characters with phonetic values, which must be compiled to form words. Not so with Egyptian and Mesopotamian writing. For those people, each word had to have its own picture.
Somewhere in Palestine in about 1500 BCE people began to assign phonetic values to their hieroglyphs. The little pictograms already represented whole words. Therefore, each one could just as easily stand for the sound of the first letter of its word. For instance, the Semitic name for an ox was “Aleph“- and so the hieroglyph for Aleph became the character for the sound of “A.” This process continued until a series of 22 pictograms had been chosen to represent 22 essential sounds in the spoken language.
The earliest examples of this new alphabetic writing come from the area of Palestine known as Phoenicia- or Canaan in Bible Scriptures. The alphabet is sometimes called by the term “Paleo-Hebrew” (that is “ancient” Hebrew) and sometimes by the term “Ugaritic” after the name of the Canaanite city where the earliest such writings were found.
The Paleo-Hebrew alphabet (Hebrew:הַכְּתָב הָעִבְרִי הַקָּדוּם) is identical to the Phoenician alphabet. At the very least it dates to the 10th century BCE. It was used as the main vehicle for writing the Hebrew language by the Israelites, both Jews and Samaritans.
It began to fall out of use by the Jews in the 5th century BCE when they adopted the Aramaic alphabet as their writing system for Hebrew, from whence the present Jewish “square-script” Hebrew alphabet descends. The Samaritans, who now number less than one thousand people, have continued to use the Old Hebrew alphabet to this day.