{"principle":"Sources are classified by function. A boundary dataset, source catalogue, analytical estimate, route reconstruction, and event seed are not treated as equivalent historical facts.","sources":[{"category":"modern reference geography","format":"Shapefile, GeoPackage, derived GeoJSON","id":"natural-earth","integration_complexity":"low","license":"public domain","name":"Natural Earth","planned_use":"modern base geography, coastlines, land polygons and reference boundaries","quality":"high for modern reference coastlines and country outlines","url":"https://www.naturalearthdata.com/"},{"category":"historical state boundaries","format":"GIS boundary dataset","id":"cshapes-2","integration_complexity":"medium","license":"academic dataset; redistribution terms require review before public raw export","name":"CShapes 2.0","planned_use":"primary modern historical state-boundary backbone from 1886 onward","quality":"high for 1886-2019 international-system states and dependent territories","url":"https://icr.ethz.ch/data/cshapes/"},{"category":"premodern and early-modern historical boundary context","format":"GeoJSON snapshot files by benchmark year, WGS84","id":"historical-basemaps","integration_complexity":"medium","license":"GPL-3.0","name":"Historical Basemaps / Alexandre R. E. Ourednik","planned_use":"source-aware historical boundary context for 3000 BCE to 1885 CE, before the CShapes international-system boundary backbone begins","quality":"broad global coverage from ancient to modern periods; work-in-progress and requires scholarly review for precise claims","url":"https://github.com/aourednik/historical-basemaps"},{"category":"historical map features","format":"OSM-style historical geodata","id":"openhistoricalmap","integration_complexity":"high","license":"varied feature-level open licenses; license tags must be preserved","name":"OpenHistoricalMap","planned_use":"premodern and regional enrichment after license-aware filtering","quality":"uneven but uniquely useful for temporally tagged historical features","url":"https://www.openhistoricalmap.org/"},{"category":"place authority and reconciliation","format":"Linked Places / JSON-LD / reconciliation platform","id":"world-historical-gazetteer","integration_complexity":"medium-high","license":"dataset-dependent","name":"World Historical Gazetteer","planned_use":"place authority, historical names, aliases, temporal place attestations","quality":"high as place-linking infrastructure; source quality depends on contributing datasets","url":"https://whgazetteer.org/"},{"category":"ancient places","format":"JSON, CSV, KML, RDF","id":"pleiades","integration_complexity":"low-medium","license":"Creative Commons Attribution 3.0","name":"Pleiades","planned_use":"ancient place authority and city/place layer","quality":"high for ancient Mediterranean, Near Eastern and classical-world places","url":"https://pleiades.stoa.org/downloads"},{"category":"crosswalk and seed records","format":"SPARQL, RDF, JSON dumps","id":"wikidata","integration_complexity":"medium","license":"CC0","name":"Wikidata","planned_use":"city, battle, university, route and entity seed layers with review status","quality":"variable; strong as identifier/alias graph, not final historical evidence","url":"https://www.wikidata.org/"},{"category":"historical population model","format":"gridded raster/netCDF/ASCII depending on version","id":"hyde","integration_complexity":"high","license":"scientific data terms; exact version terms require review","name":"HYDE historical population and land-use data","planned_use":"population density tiles and benchmark-year estimates","quality":"leading global long-run population estimate; model output, not census fact","url":"https://hyde-portal.geo.uu.nl/"},{"category":"country population series","format":"CSV/JSON","id":"owid-population","integration_complexity":"low","license":"CC BY for OWID material; underlying source terms vary","name":"Our World in Data population dataset","planned_use":"country population charts and side-panel summaries","quality":"high for public country-level population visualization","url":"https://ourworldindata.org/grapher/sources-population-dataset"},{"category":"wars, state system, religion and political-science datasets","format":"CSV and tabular datasets","id":"correlates-of-war","integration_complexity":"medium","license":"dataset-specific academic terms","name":"Correlates of War","planned_use":"modern war/state-system backbone and religion data where permitted","quality":"high for modern international-relations datasets","url":"https://correlatesofwar.org/"},{"category":"modern conflict events","format":"CSV/API/downloads","id":"ucdp","integration_complexity":"already partly integrated in AP system","license":"dataset-specific research terms with citation","name":"UCDP","planned_use":"post-1989 conflict layer and current-theater continuity","quality":"high for modern conflict events and actors","url":"https://ucdp.uu.se/"},{"category":"historical transport and route model","format":"interactive model and related data/code materials","id":"orbis","integration_complexity":"medium-high","license":"reuse terms require review before direct ingestion","name":"ORBIS Stanford Geospatial Network Model of the Roman World","planned_use":"Roman route reference and possible route layer if terms permit","quality":"excellent for Roman mobility, cost and travel-time modeling","url":"https://orbis.stanford.edu/"}],"title":"AP World History Atlas source registry","version":"2026-06-25-world-history-source-registry-v2"}