The name Izaiah is a variant of the Hebrew name Isaiah, which means "salvation of the Lord" or "the Lord is salvation." The name can be traced back to the biblical prophet Isaiah, who lived in the 8th century BC in the ancient Kingdom of Judah.

The Book of Isaiah in the Old Testament of the Bible is attributed to the prophet Isaiah, who was a prominent figure during the reign of King Hezekiah. Isaiah's teachings and prophecies played a significant role in the development of Judaism and Christianity.

The name Izaiah gained popularity during the Middle Ages, particularly among Jewish communities. One of the earliest recorded individuals with this name was Izaiah ben Abraham, a 12th-century Jewish philosopher and commentator from Spain.

In the 16th century, Izaiah ben Judah Gershon, a Jewish scholar and grammarian, made notable contributions to the study of Hebrew grammar and linguistics.

During the 17th century, Izaiah Horowitz, a renowned Kabbalist and Talmudic scholar from Prague, wrote several influential works on Jewish mysticism and ethics.

In the 19th century, Izaiah Berlin, a Russian-British philosopher and historian, was widely recognized for his contributions to the study of political theory and the concept of liberty.

Another notable individual with the name Izaiah was Izaiah Davenport, an African American Baptist minister and abolitionist who lived in the 19th century and advocated for the abolition of slavery in the United States.

Over the centuries, the name Izaiah has been used across various cultures and communities, although it remains closely tied to its Hebrew origins and biblical associations.