Yahweh, the god of the Israelites, whose name was revealed to Moses as four Hebrew consonants (YHWH) called the tetragrammaton.
After the Babylonian Exile (6th century BCE), and especially from the 3rd century BCE on, Jews ceased to use the name Yahweh for two reasons. As Judaism became a universal rather than merely local religion, the more common noun Elohim, meaning “God,” tended to replace Yahweh to demonstrate the universal sovereignty of Israel’s God over all others. At the same time, the divine name was increasingly regarded as too sacred to be uttered; it was thus replaced vocally in the synagogue ritual by the Hebrew word Adonai (“My Lord”), which was translated as Kyrios (“Lord”) in the Septuagint, the Greek version of the Hebrew Scriptures.
The Masoretes, who from about the 6th to the 10th century worked to reproduce the original text of the Hebrew Bible, replaced the vowels of the name YHWH with the vowel signs of the Hebrew words Adonai or Elohim. Latin-speaking Christian scholars substituted the Y (which does not exist in Latin) with an I or a J (the latter of which exists in Latin as a variant form of I). Thus, the tetragrammaton became the artificial Latinized name Jehovah (JeHoWaH). As the use of the name spread throughout medieval Europe, the initial letter J was pronounced according to the local vernacular language rather than Latin.
Although Christian scholars after the Renaissance and Reformation periods used the term Jehovah for YHWH, in the 19th and 20th centuries biblical scholars again began to use the form Yahweh. Early Christian writers, such as St. Clement of Alexandria in the 2nd century, had used a form like Yahweh, and this pronunciation of the tetragrammaton was never really lost. Many Greek transcriptions also indicated that YHWH should be pronounced Yahweh.
The meaning of the personal name of the Israelite God has been variously interpreted. Many scholars believe that the most proper meaning may be “He Brings into Existence Whatever Exists” (Yahweh-Asher-Yahweh). In I Samuel, God is known by the name Yahweh Teva-ʿot, or “He Brings the Hosts into Existence,” the hosts possibly referring to the heavenly court or to Israel.
The personal name of God probably was known long before the time of Moses. The name of Moses’ mother was Jochebed (Yokheved), a word based on the name Yahweh. Thus, the tribe of Levi, to which Moses belonged, probably knew the name Yahweh, which originally may have been (in its short form Yo, Yah, or Yahu) a religious invocation of no precise meaning evoked by the mysterious and awesome splendour of the manifestation of the holy.