This is a rare and interesting English locational surname. It is presumably from a place called Ranckmore, that being the early spelling of the surname as shown below, or Rankmore, except that no such place has been found in any of the known gazetters of the British Isles for the past three centuries. The only similar spelling is that of Ranmoor, found in two villages, and whilst not proven it seems very likely that this is the source of the surname. The first village is now part of the city of Sheffield in Yorkshire, and the second a hamlet near Dorking in Surrey. This place name seems to derive from the pre 7th century Olde English words 'rand' meaning an edge or ridge, and 'mor,' a morass or swamp. Locational surnames are 'from' names. That is to say names given to people after they left their original homesteads to move somewhere else. This was often the city of London, and therefore it is not suprising to find the early recording of John Ranckmore, given as being the son of Edward Ranckmore, and who was christened at St. Margaret's Westminster, on July 1st 1603, in the last year of the reign of Queen Elizabeth 1st, 1558 - 1603.