P0Historical Place Authority
World Historical Gazetteer v4
Global historical places; attestation-centric graph
- Licence posture
- Authority/service and contributed-dataset terms must be reviewed per source
- Critical caveat
- Do not copy WHG place clusters as unquestioned fact; retain source and certainty per attestation.
Historical place reconciliationVariant names and geometriesClaim-level provenance
Inspect authority ↗P0Period Authority
PeriodO
Scholarly historical, archaeological and art-historical period definitions
- Licence posture
- CC0 / public domain
- Critical caveat
- Period labels are scholarly assertions, not universal time bins.
Source-specific period definitionsAlternative periodizationsChronology disagreement cards
Inspect authority ↗P0Ancient Place Authority
Pleiades Datasets 4.1
41,480 ancient place resources as of May 2025
- Licence posture
- CC BY 3.0
- Critical caveat
- Coordinates and geometry precision vary; use numbered releases and preserve precision metadata.
Ancient-place identifiersVariant namesGeospatial references
Inspect authority ↗P0Polity Boundary Authority
Cliopatria
Worldwide polities from 3400 BCE to 2024 CE; over 1,600 entities and roughly 14,000 records
- Licence posture
- CC BY 4.0
- Critical caveat
- The polygons represent one historical interpretation and require expert review before use as allocation weights.
Polity identity reconciliationTime-varying territorial boundariesPolity lifecycle validation
Inspect authority ↗P1Polity Institutional Observations
Seshat Global History Databank
Historical polity, social-complexity, religion, institutions and related coded variables
- Licence posture
- Dataset-specific; many materials are non-commercial/share-alike
- Critical caveat
- Never treat unknown as absent or point estimates as source observations; review licence per dataset.
Polity-level institutional observationsAlternative coded interpretationsNarrative evidence for comparative hypotheses
Inspect authority ↗P1Urban Observations
Historical Urban Population: 3700 BC–AD 2000
Global spatially explicit city populations over roughly 6,000 years
- Licence posture
- Public access; verify redistribution terms at ingestion
- Critical caveat
- Coverage is sparse and inherited from Chandler/Modelski; missing cities are not zero-population cities.
City observation cardsUrban hierarchy analysisPolity/civilization urban-network projections
Inspect authority ↗P1Population Landuse Reconstruction
HYDE 3.2
Gridded population and land use from 10,000 BCE to 2015 CE
- Licence posture
- Verify source-release terms at ingestion
- Critical caveat
- HYDE is a modeled reconstruction and should never be displayed as a census or polity observation.
Environmental exposurePopulation-density scenariosLand-use change
Inspect authority ↗P0Economic Reconstruction
Maddison Project Database 2023
Country and source-defined regional GDP per capita and population through 2022
- Licence posture
- CC BY 4.0
- Critical caveat
- It does not contain CivStudy civilizations, empires or analytical patterns.
Source-country economic anchorsPublished-reconstruction observationsInputs to explicit CivStudy projections
Inspect authority ↗P1Long Run Social Economic Indicators
Clio Infra
Global social, economic and institutional indicators, strongest over the past five centuries
- Licence posture
- Dataset-specific; verify per series
- Critical caveat
- Each indicator may be constructed differently; the accompanying working paper is part of the evidence.
Wages and pricesLife expectancy and well-beingInequality
Inspect authority ↗P1_REFERENCE_ONLY_UNTIL_LICENSEModern Historical Macro
Global Macro Database v2026_06
46 variables, 239 countries, 1086–2025, 160 sources
- Licence posture
- Academic and non-profit research only; commercial use requires permission
- Critical caveat
- Do not ingest into a commercial product without permission; raw-source mode is preferable for lineage research.
Modern fiscal seriesGovernment revenue and debtTrade, inflation and unemployment
Inspect authority ↗P1_REFERENCE_ONLY_UNTIL_LICENSECultural Observations
D-PLACE / Ethnographic Atlas v3.3
Place-, language-, culture- and environment-linked ethnographic observations
- Licence posture
- CC BY-NC 4.0
- Critical caveat
- Ethnographic focal dates must be preserved; never back-project observations across centuries or civilizations.
Cultural-practice comparisonsLanguage and ecology joinsTesting broad civilization generalizations
Inspect authority ↗P1Modern Institutional Measurement
V-Dem Dataset v16
531 indicators and 251 indices; released March 2026
- Licence posture
- Verify redistribution and product-use terms
- Critical caveat
- Latent interval scores are not raw ordinal coder answers; preserve posterior or uncertainty fields where available.
Modern institutional trajectoriesMeasurement-model examplesUncertainty-aware expert-coded observations
Inspect authority ↗P1Modern Conflict Events
UCDP v26.1
Organized violence 1946–2025; georeferenced events to day and locality
- Licence posture
- Verify redistribution terms
- Critical caveat
- Event definitions and thresholds must be retained; absence from the dataset is not absence of political violence.
Modern event cardsConflict exposurePolity-event integration
Inspect authority ↗P2Historical Trade Events
Sound Toll Registers Online
1.8 million ship passages, 1497–1857; nearly complete from 1574
- Licence posture
- Verify data reuse terms
- Critical caveat
- STRO is an interpreted reduction of the original registers, not a literal source edition.
Baltic/North Sea trade networksPort and commodity flowsMerchant-network analysis
Inspect authority ↗P1Coerced Mobility And Trade
SlaveVoyages
Transatlantic and intra-American voyages plus named-person records
- Licence posture
- Open-access project; verify bulk-data reuse terms
- Critical caveat
- People are not merely flow units; preserve person-level provenance and avoid reducing the evidence to an abstract trade metric.
Atlantic coerced mobilityPort and empire-network analysisDemographic impact
Inspect authority ↗P1Paleoclimate Observations
PAGES2k Common Era proxy database
692 proxy records at 648 locations across the Common Era
- Licence posture
- Open scientific data; verify individual-record attribution requirements
- Critical caveat
- A proxy is not local annual temperature without a reconstruction model; retain archive type and temporal resolution.
Regional climate exposureClimate-event synchronizationTesting environmental narratives
Inspect authority ↗P1Modern Urbanization
UN World Urbanization Prospects 2025
237 countries/areas; estimates 1950–2025 and projections to 2050
- Licence posture
- UN terms; verify redistribution requirements
- Critical caveat
- Projections must be visually and semantically separated from estimates.
Modern urbanization cardsBridge from historical urban observations to modern dataMethodology comparison
Inspect authority ↗