By Road and by Sea

This is an interactive data study by Dr Tristan Hotham, built from open data. The map runs in your browser: explore it, search for places and switch layers. The write-up explains the method and what the data shows, and the data and code are open for anyone to reuse.

More in Romans to Tudors

The Hereford Mappa MundiThe largest surviving medieval world map set beside a modern one: its directions from Jerusalem are mostly right, but the Holy Land is drawn 4.5 times too big.Roads of the Roman Empire299,171 km of Roman road and a travel model: London was 81 days on foot from Rome, Constantinople 75 and Alexandria 180.Holy Islands20,228 European monasteries and hermitages checked against the shoreline: before 800, 4.3% stood on islands, from Skellig Michael to Iona; after 1100, about one in a hundred.The Plague Years6,848 recorded plague years in 1,172 towns, 1347 to 1900: the Black Death's first wave, a return every 13 years or so, and the last outbreaks a century later in the Ottoman Mediterranean.Britain in AD 500What the ground can place instead of neat kingdoms: 891 pieces of evidence, a sharp east of graves and west of stones, and 24 kingdoms we can name but not draw.Governing on the MoveKing John and Edward I mapped night by night: John moved on 42% of the days we can follow him, Edward on 23%.

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