This system is recorded in a 10th-century document known as the Burghal Hidage, which details the location and garrisoning requirements of thirty-three forts, whose positioning ensured that no one in Wessex was more than a long day's ride from a place of safety.
See süsteem on üles tähendatud 10. sajandi dokumendis "Burghal Hidage", mis kirjeldab 33 linnuse asukohta ja mehitamise nõudeid, ja mille paigutus kindlustas, et mitte keegi Wessexis ei olnud rohkem kui pika päevatee kaugusel turvalisest kohast.