Christopher comes from Christophoros, ‘Christ-carrier’ or ‘Christ-carried’, a Greek name therefore of the Christian period.  Even then it is not common: the Lexicon of Greek Personal Names offers a measly 10 examples, all of the 4th c. or later.  (The cut off date of the Lexicon is c. 600: no doubt the numbers would increase greatly if we went down further.)  It starts life not as a name but as an epithet, first apparently in Ignatius of Antioch (died c. 107); so the apostle Paul, for instance, can be called Christophoros.  Lampe’s Patristic Lexicon (Liddell and Scott does not admit the word!) glosses it as ‘filled or inspired by Christ’, and by analogy with an older word theophoros, ‘possessed by (a) god’, that sounds correct.  But there was a long list of pre-Christian cult titles ending in –phoros: kanephoros, basket-bearer, hydriaphoros, urn-bearer (both as seen on the Parthenon frieze), Sebastophoros, ‘carrier of (an image of) a Roman emperor’, and many more: perhaps Christophoros was felt as a kind of counter to all those pagan porters.  The shift from ‘carried, inspired by Christ’ to ‘Christ-carrying’ certainly underlies the familiar legend of St Christopher, the mighty ferryman who carried the Christ child despite his ever-increasing weight across a river.  But when did the legend in that form emerge?  Probably an authoritative account exists somewhere; here is what I have been able to assemble from my desk.  There is a 5th c. life of a huge barbarian Reprebos who on conversion took the name Christophoros and was martyred during the persecution under the emperor Decius (c. 250) (for a summary see the Oxford Saints project).  Both physically and in name he is obviously the ancestor of Christ’s ferryman, but the familiar story is not attached to him.  Nor is it there, to judge from the prose summary of a six book epic, in the Acta Sancti Christophori Martyris Versu et Prosa Descripta of Walter, Bishop (ultimately) of Speyer (born 967).  But the hugely influential Golden Legend of Jacopo de Voragine (born c. 1230) has it, and its fortune was secured.  St Christopher became a protector against sudden death: ‘be sure you will not die a bad death on that  day, if you look upon an image of St. Christopher’ (illa nempe die morte mala non morieris/Cristoferi sancti speciem quicumque tueris); whence all those portraits inside and outside churches.  There was some resistance during the Reformation and Counter Reformation.  Erasmus spoke with contempt of ‘those who beguile themselves with the silly but pleasing notion that if they look upon a picture or image of St. Christopher — that huge Polyphemus, — they will not die that day.’  But dangerous modern forms of travel (motorways and flying) have earnt the Saint a renewed popularity in Catholic and Orthodox countries as patron of travellers.   Google ‘St Christopher: images’, and you will find yourself in a world of protective necklaces and bracelets. 

Predictably, variants of the name are pan-European. It is first attested in this country in 1201, and has oscillated in popularity since: very low in Victorian England, a boom from about the 40s to the 80s of the last century when it briefly reached the top of the male chart, then a steep decline.  Names are a dramatic demonstration of how individuals making their own free choices are none the less controlled by currents of fashion they know not of: I note that my own parents were so swayed when they called me Christopher (admittedly only as a spare middle name) in 1950 when the boom was getting under way.     

christopher by bellini with gold frame.  christopher looks up to the right, walking oon water.