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The Tree of Europe · Person

Cosimo I de’ Medici

He consolidated Medici power and conquered Siena, extending his territorial dominion. The acquisition of the title of Grand Duke of Tuscany completed that political transformation.

1519 – 1574Grand DukeMedici
Explore this family · Spanish AtlasBack to people
Portrait of Cosimo I de’ Medici
Historical portraitCosimo I de’ Medici in armourBronzino · 1545Public domain · PD-Art / PDM 1.0 · Source

This complete profile is available in English. Bibliographic titles retain their original language. Links marked ES open the Spanish edition.

Historical profile

Key details

Birth: 12 June 1519 Documented

Death: 21 April 1574 Documented

Role: Grand Duke

Dynasty: Medici

Territories: Tuscany (ES) · Florence (ES)

Recorded governments and reigns
Duke · Florence · Duchy Pending review1537–1569Effective rule
Grand duke · Tuscany · Grand duchy Pending review1569–1574Effective rule
Family network

Recorded relationships

Parents
Giovanni de’ MediciPending reviewMaria Salviati · ESPending review
Partners
Eleanor of ToledoPending review
Children
Crowns and unions

Their titles over time

Follow the changing territories and offices of Cosimo I de’ Medici. Each title retains its own status.

Governments in 1569

  • FlorenceDuke
    View titles and jurisdictions
  • TuscanyGrand duke
    View titles and jurisdictions

Annual dates: overlap within one year does not prove that two offices were held on the same day. Regencies and co-rulerships retain their labels.

Documentation

Sources for this profile

Biographical and contextual references in their original language. Sources and methodology.

Evidence for this profile

7 recorded claims · 5 without a claim-specific source. Context references do not by themselves verify every fact.

Dates (2/2 with a precise source)
Family and relationships (0/3 with a precise source)
  • FatherPending review

    Giovanni de’ Medici

    A precise source has not yet been added.
    No individual review recorded ·
  • MotherPending review

    Maria Salviati

    A precise source has not yet been added.
    No individual review recorded ·
  • Marriage or partnershipPending review

    Eleanor of Toledo

    A precise source has not yet been added.
    No individual review recorded ·
Governments (0/2 with a precise source)
  • GovernmentPending review

    Duke · Florence · 1537–1569

    A precise source has not yet been added.
    No individual review recorded ·
  • GovernmentPending review

    Grand duke · Tuscany · 1569–1574

    A precise source has not yet been added.
    No individual review recorded ·
Biographical and contextual references (3)
Editorial history
  • 2026-10-12 · Claim registry added; existing historical data kept. Specific sourcing remains to be reviewed.
  • 2026-10-08 · Claim registry added; existing historical data kept. Specific sourcing remains to be reviewed.
  • 2026-10-04 · Claim registry added; existing historical data kept. Specific sourcing remains to be reviewed.
  • 2026-10-04 · Claim registry added; existing historical data kept. Specific sourcing remains to be reviewed.
  • 2026-10-03 · Claim registry added; existing historical data kept. Specific sourcing remains to be reviewed.
  • 2026-09-30 · The duchy is limited to Dijon and Autun; each other fief now enters the map only under its dated ruler. John III of Namur and the Nevers/Rethel branch were added. The previous shape combined later counties and unrelated lands as if all belonged to the duchy from 1363.
  • 2026-09-28 · Claim registry added; existing historical data kept. Specific sourcing remains to be reviewed.

Keep exploring

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