Isaac II Angelos
E891975
Isaac II Angelos was a Byzantine emperor of the late 12th century whose turbulent reign was marked by internal strife, heavy taxation, and the empire’s growing vulnerability leading up to the Fourth Crusade.
All labels observed (3)
| Label | Occurrences |
|---|---|
| Isaac II Angelos canonical | 6 |
| Emperor Isaac II Angelos | 2 |
| Byzantine emperor Isaac II Angelos | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T10284530 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Isaac II Angelos Context triple: [Alexios III Angelos, sibling, Isaac II Angelos]
-
A.
Alexios IV Angelos
Alexios IV Angelos was a Byzantine emperor whose alliance with the leaders of the Fourth Crusade led to the crusaders’ intervention in Constantinople and the eventual sack of the city in 1204.
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B.
Alexios III Komnenos
Alexios III Komnenos was a Byzantine emperor of Trebizond from the 14th century, known for consolidating his realm along the Black Sea coast and patronizing Orthodox monastic institutions.
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C.
Byzantine Emperor Alexios III Angelos
Byzantine Emperor Alexios III Angelos was a late 12th- to early 13th-century ruler of the Byzantine Empire whose weak leadership and mismanagement contributed to the empire’s decline and the events leading up to the Fourth Crusade.
-
D.
John III Doukas Vatatzes
John III Doukas Vatatzes was a 13th-century Byzantine emperor of Nicaea renowned for restoring stability, economic prosperity, and military strength to the exiled Byzantine state.
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E.
John II Komnenos
John II Komnenos was a 12th-century Byzantine emperor known for his effective military campaigns, administrative reforms, and efforts to restore the strength and territory of the Byzantine Empire.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Isaac II Angelos Target entity description: Isaac II Angelos was a Byzantine emperor of the late 12th century whose turbulent reign was marked by internal strife, heavy taxation, and the empire’s growing vulnerability leading up to the Fourth Crusade.
-
A.
Alexios IV Angelos
Alexios IV Angelos was a Byzantine emperor whose alliance with the leaders of the Fourth Crusade led to the crusaders’ intervention in Constantinople and the eventual sack of the city in 1204.
-
B.
Alexios III Komnenos
Alexios III Komnenos was a Byzantine emperor of Trebizond from the 14th century, known for consolidating his realm along the Black Sea coast and patronizing Orthodox monastic institutions.
-
C.
Byzantine Emperor Alexios III Angelos
Byzantine Emperor Alexios III Angelos was a late 12th- to early 13th-century ruler of the Byzantine Empire whose weak leadership and mismanagement contributed to the empire’s decline and the events leading up to the Fourth Crusade.
-
D.
John III Doukas Vatatzes
John III Doukas Vatatzes was a 13th-century Byzantine emperor of Nicaea renowned for restoring stability, economic prosperity, and military strength to the exiled Byzantine state.
-
E.
John II Komnenos
John II Komnenos was a 12th-century Byzantine emperor known for his effective military campaigns, administrative reforms, and efforts to restore the strength and territory of the Byzantine Empire.
- F. None of above. chosen
Statements (49)
| Predicate | Object |
|---|---|
| instanceOf |
Byzantine emperor
ⓘ
Eastern Roman emperor ⓘ monarch ⓘ |
| birthDate | c. 1156 ⓘ |
| birthPlace | Constantinople NERFINISHED ⓘ |
| capitalDuringReign | Constantinople NERFINISHED ⓘ |
| causeOfDeath | natural causes (possibly complications after imprisonment) ⓘ |
| child |
Alexios IV Angelos
NERFINISHED
ⓘ
John Angelos NERFINISHED ⓘ Manuel Angelos NERFINISHED ⓘ |
| coRuler | Alexios IV Angelos NERFINISHED ⓘ |
| country | Byzantine Empire ⓘ |
| deathDate | January 1204 ⓘ |
| deathPlace | Constantinople NERFINISHED ⓘ |
| era |
early 13th century
ⓘ
late 12th century ⓘ |
| familyName | Angelos NERFINISHED ⓘ |
| father | Andronikos Doukas Angelos NERFINISHED ⓘ |
| givenName | Isaac NERFINISHED ⓘ |
| historicalPeriod | late Komnenian and Angelid period of the Byzantine Empire ⓘ |
| knownFor |
contributing to the decline of Byzantine power before the Fourth Crusade
ⓘ
financial mismanagement ⓘ heavy taxation ⓘ weak central authority ⓘ |
| languageSpoken | Medieval Greek ⓘ |
| memberOf | Angelos dynasty NERFINISHED ⓘ |
| militaryConflict |
conflicts with the Kingdom of Hungary
ⓘ
conflicts with the Seljuk Turks ⓘ wars with the Bulgarians and Vlachs ⓘ |
| mother | Euphrosyne Kastamonitissa NERFINISHED ⓘ |
| notableEvent |
deposed again in 1204 shortly before the sack of Constantinople
ⓘ
deposed and blinded by his brother Alexios III Angelos in 1195 ⓘ faced Norman invasion of the Balkans in 1185–1186 ⓘ faced rebellion of the Bulgarians and Vlachs leading to the Second Bulgarian Empire ⓘ restored to the throne by the forces of the Fourth Crusade in 1203 ⓘ rose to power after popular uprising against Andronikos I Komnenos in 1185 ⓘ ruled jointly with his son Alexios IV Angelos after 1203 ⓘ |
| positionHeld |
Byzantine emperor
ⓘ
Emperor of the Romans NERFINISHED ⓘ |
| predecessor | Andronikos I Komnenos NERFINISHED ⓘ |
| reignEnd |
1195
ⓘ
1204 ⓘ |
| reignStart |
1185
ⓘ
1203 ⓘ |
| religion | Eastern Orthodox Christianity ⓘ |
| spouse |
Herina (first wife, name uncertain)
NERFINISHED
ⓘ
Margaret of Hungary NERFINISHED ⓘ |
| successor | Alexios III Angelos NERFINISHED ⓘ |
| title | Basileus ton Rhomaion (Emperor of the Romans) NERFINISHED ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Isaac II Angelos Description of subject: Isaac II Angelos was a Byzantine emperor of the late 12th century whose turbulent reign was marked by internal strife, heavy taxation, and the empire’s growing vulnerability leading up to the Fourth Crusade.
Referenced by (9)
Full triples — surface form annotated when it differs from this entity's canonical label.
subject surface form:
Alexios III Angelos
subject surface form:
Alexios III Angelos
subject surface form:
Alexios III Angelos
this entity surface form:
Emperor Isaac II Angelos
this entity surface form:
Byzantine emperor Isaac II Angelos
this entity surface form:
Emperor Isaac II Angelos