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Hadrian adopts Antoninus Pius as successor in 138 CE

On 25 February 138 Hadrian adopted Antoninus Pius, binding him to adopt Marcus Annius Verus and Lucius, son of Aelius. The dated succession instrument is not the earlier opacity of 136 and not the four consulars of 118. In the causal graph this event strengthens Democratic Resilience, a driver that strengthens Having a say in government — an improving welfare path.

Read the full account

On 25 February 138 Hadrian adopted Antoninus Pius, binding him to adopt Marcus Annius Verus and Lucius, son of Aelius. The dated succession instrument is not the earlier opacity of 136 and not the four consulars of 118. Hadrian’s documented role is: He adopted Titus Aurelius Antoninus after Aelius Caesar’s death, requiring Antoninus to adopt Marcus and Lucius. The Senate confirmed; Hadrian was dying. A 138 named adoption is the closing instrument of that file. Later editors, printers, and excavators remain named where they appear. The Senate confirmed; Hadrian was dying.

Context

Aelius Caesar had died on 1 January 138. A forced double adoption is shared with Antoninus. A peaceful 138 is not a unique welfare series. Later Antonine piety toward Hadrian is neighbouring. Named others on the file: Antoninus Pius, Marcus, young Lucius, and the Senate share the adoption. The public setting is the file around 0138-02-25. The instrument stays Hadrian adopts Antoninus Pius as successor in 138 CE. The setting of Hadrian adopts Antoninus Pius as successor in 138 CE is the public file around 0138-02-25. Driver democratic-resilience is attached because the significance names a mechanism from this act, not because a standing list needed coverage.

Confidence is stated on the impact path, not hidden in adjectives. Mixed effects of Hadrian adopts Antoninus Pius as successor in 138 CE are separate paths.

Why it matters

Complex shared with Antoninus’s later reign. Welfare reading improving. The attached mechanism is A dated double-adoption instrument transferred succession by named public act rather than another 138 civil war. Lag to any modern indicator is not treated as zero. This path is attached because the mechanism is named from this act, not because a driver list needed coverage. The welfare reading on this path is improving.

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

Who was responsible

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

  • Hadrian

    Person

    Direct responsibility

    responsibility level 0.44 · verified

    He adopted Titus Aurelius Antoninus after Aelius Caesar’s death, requiring Antoninus to adopt Marcus and Lucius. The Senate confirmed; Hadrian was dying.

What changed

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

    1. FactHadrian adopts Antoninus Pius as successor in 138 CE
    2. strengthensDriverDemocratic Resilience
    3. strengthensIndicators (3)Having a say in government
    Improving path

    impact weight 0.4 · Effect from 25 February 138 · verified

    A dated double-adoption instrument transferred succession by named public act rather than another 138 civil war.

    • Strengthens · Relationship strength 0.28 (weight 0.4 × strength 0.7)

      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

    • Strengthens · Relationship strength 0.18 (weight 0.4 × strength 0.45)

      Observed

      0.53 score from 0 to 1 · 0.34 below the normal line (2024)

      Worse than normal

      125 readings, 1900–2024: rose from 0.17 score from 0 to 1 to 0.53 score from 0 to 1.

      Above normal = better

    • Strengthens · Relationship strength 0.18 (weight 0.4 × strength 0.45)

      Observed

      0.55 index score (0-1) · 0.26 below the normal line (2024)

      Worse than normal

      Above normal = better

Evidence

The sources behind this fact and its verification state.

Verified2 sources on file
  1. 1.Britannica — Antoninus Pius, adoption 138Encyclopaedia Britannica · High credibility · verified
  2. 2.Britannica — HadrianEncyclopaedia Britannica · High credibility · verified
What the sources establish

Britannica’s Hadrian and Antoninus pages independently date the 138 adoption. Official: Britannica — Hadrian, adoption of Antoninus (https://www.britannica.com/biography/Hadrian (opens in a new tab); Encyclopaedia Britannica). Independent: Britannica — Antoninus Pius, adoption 138 (https://www.britannica.com/biography/Antoninus-Pius (opens in a new tab); Encyclopaedia Britannica). The two URLs are different pages. Where the carrier is a later edition or a received narrative, that limit is stated rather than upgraded to an autograph. Official carrier: Britannica — Hadrian, adoption of Antoninus (https://www.britannica.com/biography/Hadrian (opens in a new tab); Encyclopaedia Britannica). Independent carrier: Britannica — Antoninus Pius, adoption 138 (https://www.britannica.com/biography/Antoninus-Pius (opens in a new tab); Encyclopaedia Britannica).

Established: 138 adoption of Antoninus with further adoptions required. Not established: that 136’s opacity is this same act. Established: a sourced public record of Hadrian adopts Antoninus Pius as successor in 138 CE under 0138-02-25.

Shared responsibility is part of Hadrian adopts Antoninus Pius as successor in 138 CE. Naming Hadrian does not delete co-authors, institutions, or later transmitters. The lag from 0138-02-25 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.

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

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

Causal path

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

  1. ActorHadrian
  2. contributed toFactHadrian adopts Antoninus Pius as successor in 138 CE
  3. strengthensDriverDemocratic Resilience
  4. strengthensIndicatorHaving a say in government

Cite this page

Factrail. (2026). Hadrian adopts Antoninus Pius as successor in 138 CE. Factrail. https://factrail.ai/facts/had-antoninus-adoption-138

https://factrail.ai/facts/had-antoninus-adoption-138

Accessed 16 October 2026.

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

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