In Die zentralen Orte in Süddeutschland (1933) Christaller derived a settlement hierarchy from two properties of every good or service: its range, the distance people will travel for it, and its threshold, the minimum market it needs to survive. Competing suppliers therefore divide a uniform plain into hexagonal market areas nested at successive levels - hamlet, village, town, regional centre - with higher-order goods concentrated in fewer, larger places. He fitted the model to southern Germany using settlement sizes and telephone connections. The theory was later applied by Himmler's planning staff to the intended resettlement of occupied Poland, work in which Christaller took part.
It gave planning the catchment, the service radius and the settlement hierarchy - the reasoning that sizes a school, clinic, market or new town and spaces them across a region. Postwar new-town programmes, Dutch polder settlement, Indian and Israeli regional plans and retail-impact assessment all still run on it.
See it on the timeline →