Isaiah (UK: or US: ; Hebrew: יְשַׁעְיָהוּ, Yəšaʿyāhū, "Yahweh is salvation"; also known as Isaias or Esaias from Greek: Ἠσαΐας) was the 8th-century BC Israelite prophet after whom the Book of Isaiah is named. The text of the Book of Isaiah refers to Isaiah as "the prophet", but the exact relationship between the Book of Isaiah and the actual prophet Isaiah is complicated. The traditional view is that all 66 chapters of the book of Isaiah were written by one man, Isaiah, possibly in two periods between 740 BC and c. 686 BC, separated by approximately 15 years.
https://en.wikipedia.org/wiki/Isaiah