Quadripoint
A quadripoint is a point on the Earth that touches the border of four distinct territories. The term has never been in common use—it may not have been used before 1964 when it was possibly invented by the Office of the Geographer of the United States Department of State. The word does not appear in the Oxford English Dictionary or Merriam-Webster Online dictionary, but it does appear in the Encyclopædia Britannica, as well as in the World Factbook articles on Botswana, Namibia, Zambia, and Zimbabwe, dating as far back as 1990.
An early instance of four political divisions meeting at a point is in England (attested in the Domesday Book, 1086, and mentioned since 969 if not 772); it combined until 1931 the English shires/counties of Gloucester, Oxford, Warwick and Worcester.
The earliest known quadripoint involving modern nation states existed from 1817 to 1821 where the present Alabama–Mississippi state line crossed the 31st parallel border between Spain and the United States. During that period, the part of West Florida between the Pearl and Perdido rivers (which Spain still owned but the United States forcibly occupied and annexed in 1810 after belatedly claiming it as part of the Louisiana Territory purchased from France in 1803) was subdivided and allocated partly to the State of Mississippi and partly to the Territory (and later State) of Alabama. There resulted, at the intersection of demarcated boundaries, an international quadripoint of four territories, which in the United States were named (clockwise) Baldwin and Mobile Counties of Alabama and Jackson and Greene Counties of Mississippi, though Mobile and Jackson Counties were actually still in Spain.
Between 1839 and 1920 there was a quadripoint at the convergence of Belgium, Prussia/Germany, the Netherlands, and Moresnet at Vaalserberg 50°45′N 6°01′E / 50.75°N 6.02°E. Moresnet was never truly a country but rather only a neutral territory or condominium of the Netherlands and Prussia (originally), and of Belgium and Germany (ultimately). If Moresnet is counted as a country, then national borders came together in this point from five different directions during the existence of Moresnet and the World War I, although never more than four at the same time. Subsequent political changes have restored its quadripartition along municipal lines (Kelmis, Plombieres within Belgium) since 1976 (though it has also enjoyed fivefold partition along municipal lines at times).
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