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A fifty-year peace with the Sasanians is concluded

In 562 Justinian’s government and Khosrow I concluded a fifty-year peace: subsidy, regulation of Lazica, and clauses on Christians in the Persian realm, preserved in later excerpts of Menander Protector. This is not the 532 Eternal Peace and not the 540 sack. In the causal graph this event weakens Political Polarization, a driver that weakens Having a say in government — an improving welfare path.

Sources: [1][2]

Read the full account

In 562 Justinian’s government and Khosrow I concluded a fifty-year peace: subsidy, regulation of Lazica, and clauses on Christians in the Persian realm, preserved in later excerpts of Menander Protector. This is not the 532 Eternal Peace and not the 540 sack.

Context

Both sides were exhausted. Justinian was old; Khosrow had other fronts. The treaty’s ‘fifty years’ did not bind their successors as a charm. Sharing the instrument with Khosrow is mandatory. Polarization here is interstate.

Why it matters

Improving polarization path at the end of the reign. Medium confidence.

If a number is not in the two records named above, it is not supplied here.

Who was responsible

Contribution type and responsibility level for each recorded actor — not sole-author shorthand.

  • Justinian I

    Person

    Direct responsibility

    responsibility level 0.32 · verified

    His diplomats concluded a fifty-year peace with Khosrow. The king of kings signed as an equal; subsidies continued.

What changed

Fact → Driver → Indicator. Relationship strength orders the paths; it is not the observed indicator movement.

    1. FactA fifty-year peace with the Sasanians is concluded
    2. weakensDriverPolitical Polarization
    3. weakensIndicators (2)Having a say in government
    Improving path

    impact weight 0.35 · Effect from 1 January 562 · verified

    A long eastern peace reduced immediate war polarization on the Mesopotamian and Caucasian fronts at the end of the reign.

    • Having a say in government

      via Political Polarization

      Better

      Weakens · Relationship strength 0.16 (weight 0.35 × strength 0.45)

      Observed

      29.8% of population aged 16-65 years · 8.13 below the normal line (2023)

      Worse than normal

      Two readings: 30.2% of population aged 16-65 years (2021) and 29.8% of population aged 16-65 years (2023).

      20212023

      Above normal = better

    • Rule of Law Gap from the Highest Governance Score

      via Political Polarization

      Better

      Strengthens · Relationship strength 0.16 (weight 0.35 × strength 0.45)

      Observed

      43.9 Score · 43.9 above the normal line (2024)

      Worse than normal

      26 readings, 1996–2024: rose from 43 Score to 43.9 Score.

      Normal is zero · any amount = worse

Evidence

The sources behind this fact and its verification state.

Verified2 sources on file
  1. 1.Late antique diplomatic fragments tradition (Menander via standard public carriers)The Latin Library / public late-antique text portal · High credibility · verified
  2. 2.Britannica — Khosrow I, peace and later wars with JustinianEncyclopaedia Britannica · High credibility · verified
What the sources establish

Britannica independently notes the 562 settlement. Standard translations of Menander independently carry the terms. Procopius had already died; he is not the 562 carrier.

Established: a 562 Roman–Sasanian peace was concluded in Justinian’s last years.

Confidence is stated on the impact path, not hidden in adjectives. Mixed effects of A fifty-year peace with the Sasanians is concluded are separate paths.

Later competitions, monuments, translations, UNESCO listings, museums, and adaptations are not converted into extra lifetime acts.

That reading is an impact-path choice, not a property stored on the Fact itself.

Shared responsibility is part of A fifty-year peace with the Sasanians is concluded. Naming Justinian I does not delete co-authors, institutions, or later transmitters. The lag from 0562-01-01 to any measured indicator is not treated as zero. Alternative explanations — weather, other armies, later statutes, or independent cultural change — remain live where the sources do not close them.

Causal path

How this event connects to drivers and indicators in the graph.

  1. ActorJustinian I
  2. contributed toFactA fifty-year peace with the Sasanians is concluded
  3. weakensDriverPolitical Polarization
  4. weakensIndicatorHaving a say in government

Cite this page

Factrail. (2026). A fifty-year peace with the Sasanians is concluded. Factrail. https://factrail.ai/facts/er-justinian-fifty-year-peace-0562

https://factrail.ai/facts/er-justinian-fifty-year-peace-0562

Accessed 16 October 2026.

By the Factrail desk · Method: how we source and score · Last reviewed

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