As anyone in the family will tell you, people rarely believe that we know how to spell our own name and will usually write down something else when we clearly say L-A-N-F-E-A-R. It was ever thus. Here is a list of variants on our name found so far in documents (censuses, parish registers etc.) in approximate order of frequency of occurrence, including some names which may not be related to the family.
Lanfear, Lanfier, Lanfire, Lanfere, Lamphire, Lanphier, Lamphier, Lanfiere, Langfield, Lamphere, Langfear, Lanfyre, Lanfeere, Langfere, Lanfer, Lanfeer, Lampher, Lanfeare, Landfield, Landfear, Lanfeir, Lamfear, Lanfair, Lampheir, Lamfier, Langfer, Lamphir, Lanfilde, Lanfeire, Lanifier, Landfer, Lamphear, Lampheare, Lamfire, Lamfer, Lamfeere, Langfire, Langfell, Landfere, Lanphere, Lanpher, Lanpheare, Langfielde, Lanfyer, Lanfield, Lanfeld, Lanfar, Landfire, Landfier, Landfar, Landfair, Lampyer, Lampier, Lamphyre, Lampfield, Lamper, Lamfeir, Lamfeare, Lansear, Lankfill, Langford, Langfild, Langfeld, Langfaire, Lanfior, Lanfild, Lanfiar, Lanfeur, Lanfaw, Lanfare, Lanefer.
Despite this significant variation in the form of the name in the past, the spelling has become pretty uniform is the last century or so with most people adopting Lanfear in the UK and forms with PH like Lanphear being more common in the USA.
These etymologies have been extracted from books on surnames but I am sceptical about the suggested Celtic origins for the family name. Whilst it is true that llan fair is Welsh, and Llanfair appears in many place names in Wales, the name is not found it Wales until the 19th Century when some families from the West Country migrated there. The highest concentration of the Lanfear name is found in North Wiltshire, well away from any Celtic influence, where it appears in records back to the 16th Century.
Lower cites Arthur as the source of this etymology.
Lanfear is a name that was represented by De Lanfar, or De Lanfare, in London in the reign of Edward I (Hundred Rolls).
Guppy classified the name as being peculiar to the county of Berkshire (that is confined mostly to that county) and estimated its frequency of occurrence to be 9 per 10,000 of the population.
Another suggested derivation for the name, more consonant with the theory of a Huguenot origin for the family, is from the French l’âme fière, meaning proud soul.
The name Lanfer exists in Germany. The German name is derived from Landwehr, which is the name of the local militia in the Middle Ages
If you think that Lanfear means Daughter of the Night then you may be looking for a Wheel of Time site.
The Office of National Statistics has a database of over one million names occurring in England, Wales and the Isle of Mann in September 2002. The name Lanfear is borne by 489 individuals in the database in position 11561 in order of frequency of occurrence.
The database was established in 1998. Births have been added but deaths have not been removed. The counts may also contain duplicate entries, mis-spellings and people like me who no longer live in Great Britain. Experience suggests that a better estimate of the number of Lanfears in England and Wales is to multiply the above figure by 0.93, giving around 450.
The number of Lanfears that have lived since the start of Parish Registers in the 16th Century is estimated by multiplying the database count by 3.5, giving around 1700. My own genealogical database is approaching this size so I do not expect to find any further large swathes of Lanfears.