The Tree of Europe · Person

Frederick III of Sicily

«the Simple»

He governed a Sicily weakened by aristocratic conflicts and Neapolitan pressure. The Avignon agreement of 1372 provided a new framework for recognition of the island’s crown. His daughter Mary inherited the kingdom and became the focus of struggles to control the succession.

1341 – 1377KingBarcelona-Sicily · ES

Explore this family · Spanish Atlas Back to people

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: 1341 Pending review

Death: 1377 Pending review

Role: King

Other recorded names: Federico IV de Sicilia

Dynasty: Barcelona-Sicily · ES

Territories: Trinacria (ES) · Athens (ES) · Duchy of Neopatras (ES)

Recorded governments and reigns

King · Trinacria · Reign Pending review1355–1377Effective rule

Duke · Athens · Duchy Documented1355–1377Effective ruleHe inherited the duchies from his cousin Frederick I and governed them from Sicily through vicars-general.

Duke · Duchy of Neopatras · Duchy Documented1355–1377Effective ruleJoined to Athens and inherited with it in 1355.

Family network

Recorded relationships

Parents

Peter II of SicilyPending reviewElizabeth of Carinthia · ESPending review

Partners

Antonia of Baux · ESPending review

Children

Mary of Sicily

Crowns and unions

Their titles over time

Follow the changing territories and offices of Frederick III of Sicily. Each title retains its own status.

Period

Governments in 1355

Trinacria and the duchies of Athens and Neopatras3 titles and offices
View titles and jurisdictions
- Trinacria · ESKing · Effective rule1355–1377
- Athens · ESDuke · Effective rule1355–1377 · He inherited the duchies from his cousin Frederick I and governed them from Sicily through vicars-general.
- Duchy of Neopatras · ESDuke · Effective rule1355–1377 · Joined to Athens and inherited with it in 1355.
Frederick III of Sicily inherited the Catalan duchies in Greece in 1355 and ruled them as duke through vicars-general. The duchies retained their own institutions. Source for this grouping

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

8 recorded claims · 6 without a claim-specific source. Context references do not by themselves verify every fact.

Dates (0/2 with a precise source)

BirthPending review
1341
A precise source has not yet been added.
No individual review recorded ·
DeathPending review
1377
A precise source has not yet been added.
No individual review recorded ·

Family and relationships (0/3 with a precise source)

FatherPending review
Peter II of Sicily
A precise source has not yet been added.
No individual review recorded ·
MotherPending review
Elizabeth of Carinthia
A precise source has not yet been added.
No individual review recorded ·
Marriage or partnershipPending review
Antonia of Baux
A precise source has not yet been added.
No individual review recorded ·

Governments (2/3 with a precise source)

GovernmentPending review
King · Trinacria · 1355–1377
A precise source has not yet been added.
No individual review recorded ·
GovernmentDocumented
Duke · Athens · 1355–1377
He inherited the duchies from his cousin Frederick I in 1355.
Gran Enciclopèdia Catalana · Ducat d’Atenes · The duchies passed to Frederick III of Sicily in 1355; Peter the Ceremonious accepted the sovereignty offered to Eleanor of Sicily and united them with the Crown in 1380; Nerio Acciaiuoli captured Athens in 1388.
Reviewed on 2026-10-19 by El Árbol de Europa ·
GovernmentDocumented
Duke · Duchy of Neopatras · 1355–1377
Neopatras remained joined to the Duchy of Athens.
Gran Enciclopèdia Catalana · Ducat d’Atenes · The duchies passed to Frederick III of Sicily in 1355; Peter the Ceremonious accepted the sovereignty offered to Eleanor of Sicily and united them with the Crown in 1380; Nerio Acciaiuoli captured Athens in 1388.
Reviewed on 2026-10-19 by El Árbol de Europa ·

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.

Follow this person through history

Story · Spanish original

The kingdom divided in two

Hohenstaufen, Anjou and Aragon contend for Sicily and Naples

Start reading

Keep exploring

More paths from Frederick III of Sicily