Scholars generally agree that the Book of Isaiah was not written all at once, but took shape over several centuries, roughly from the 8th to the 4th century BCE.

Quick Scoop: Core Timeline

Most academic reconstructions divide Isaiah into major sections with different dates.

  • Proto‑Isaiah (chapters 1–39):
    • Usually dated to the 8th century BCE , during the lifetime of the historical prophet Isaiah of Jerusalem, in the days of kings like Uzziah, Ahaz, and Hezekiah (around 740–700 BCE).
* Reflects Assyrian‑era crises and oracles of judgment and hope addressed to Judah.
  • Deutero‑Isaiah (chapters 40–55):
    • Commonly dated to the 6th century BCE , during the Babylonian exile , long after Isaiah of Jerusalem.
* Speaks as if Jerusalem has already fallen and the people are in exile, focusing on comfort, restoration, and the hope of return.
  • Trito‑Isaiah (chapters 56–66):
    • Often dated to the late 6th–4th century BCE , in the post‑exilic period after some Judeans have returned from Babylon.
* Addresses life in a struggling restored community, with themes of worship, justice, and inclusion of foreigners.

Single Author vs Multiple Authors

There are two main viewpoints about when and by whom Isaiah was written.

  • Traditional view (single Isaiah, ~8th century BCE):
    • Holds that the prophet Isaiah himself wrote (or dictated) the entire book during his ministry, roughly between 739 and 681 BCE.
* Emphasizes continuity of theology and accepts long‑range predictive prophecy as a reason later‑looking passages can still come from Isaiah.
  • Critical scholarly view (multiple stages over centuries):
    • Sees Isaiah as a composite work , formed and expanded by different prophetic and scribal groups across about 200 years or more.
* Points to shifts in language, historical setting, style, and themes as evidence that later chapters come from exilic and post‑exilic periods.

Here is a simple overview:

[3][5] [1][5] [5][1]
Section Chapters Approx. Date Typical Setting
Proto‑Isaiah 1–39 8th century BCE Assyrian threat in Judah, time of Isaiah of Jerusalem
Deutero‑Isaiah 40–55 6th century BCE Judeans in Babylonian exile
Trito‑Isaiah 56–66 Late 6th–4th century BCE Post‑exilic community back in the land

How the Book Was Compiled

Modern scholarship often describes Isaiah as a growing tradition rather than a single‑moment composition.

  • Prophetic oracles first circulated orally and in small written collections connected to Isaiah and his circle in the 8th century.
  • Later scribes and prophetic groups shaped, expanded, and re‑framed those traditions for new historical crises (exile and return), eventually producing the unified scroll seen at Qumran in the Great Isaiah Scroll (1st century BCE).

Very Short Answer (TL;DR)

  • If you ask, “When was Isaiah written?” , a traditional answer: around 739–681 BCE, during the life of the prophet Isaiah.
  • From a critical academic angle: the book was composed and edited in stages from the 8th through at least the 6th, and probably into the 4th century BCE.

Information gathered from public forums or data available on the internet and portrayed here.