Most people who know anything about Finland can spot a Finnish surname a mile off. Unlike Germanic surnames, Finnish surnames are very distinctive, especially the ones with the characteristic 'nen' ending as in 'Halonen' and 'Vanhanen.' Often when you ask a Finn, 'What does your surname mean?' they will have no idea, or it will mean something idiosyncratic to the foreign ear.
Surnames are actually surprisingly new to Finland. In the east of the country, they may have begun use in around the thirteenth century but it wasn't until nineteenth century that everybody in Western Finland had a fixed surname. As most of the Finns worked on farms, the names reflected this and this is where the famous 'nen' ending comes in. It means 'place of' or 'from' and put onto the end of mind boggling number of names. The ancestors of people with the 'nen' surnames most likely worked on a farm or in a certain area of a farm, however it can be a diminutive meaning 'little' or simply refer to being from a town or country as in 'Ruotslainen'. Finland's most popular surname is 'Virtanen' (over 23000 people) followed by a number of other 'nen' names. These include 'Mäkinen' ('of the hill').
But things start to change at number 5. The fifth most popular surname is 'Mäkelä' and as with all names ending 'lä' it is likely to have come from the east of Finland where 'lä' on the end of the a word is used to mean 'of'. So 'Mäkelä' also means 'of the hill.' It becomes clear how these people's ancestors were originally referred to. Mikko Jussilä was 'Michael of Jussi's farm.' In general, most Finnish names refer to something to do with farming, a part of a farm or nature. The rare name 'Mäki-Lepilampi' means 'Hill-Alder tree Pond.' Presumably there was already somebody living nearer the hill so the originator of this name had a house more towards the pond where there was an alder tree. 'Aho' means 'clearing', 'Rehumäki' means 'horse feed (provender) hill', Paasikivi means 'big stone,' 'Laine' refers to a ripple in a river, 'Kataja' means 'Juniper bush' and so on and so forth.
Some names lack the 'farming' logic but they refer to nature in some way. This tends to reflect nineteenth migrations in which country people turned-up in small towns and cities without a surname. Accordingly they had to invent one. 'Laine' (wave) was popular as was 'Nurmi' (grassland). The more peculiar 'nature names' may well reflect this migration and sometimes 'nen' would be added to the end to give them a definite Finnish flavour.
Some Finnish surnames, though, have far more complex pedigrees and quite a few are not ultimately Finnish at all. The surnames 'Kortelainen' and 'Kaartinen' may well all be related and be Finnicised Jewish names. There are also various names that were originally Swedish but were translated into Finnish during periods of nationalist fervour. Likewise, Finnish-speakers who rose up the social ladder before the national awakening and changed their language to Swedish might adopt a Swedish translation of their name.
In a few cases, especially with people who joined the army, clergy or civil service, their name would be translated into Latin as in 'Manelius' and 'Topelius'. And many Finnish-speakers simply retain Swedish names which reflect a completely different history and set of meanings. Some surnames are Finnicised corruptions of Sami, Estonian or even Russian and Tartar words.
Finns are allowed to change their surname by deed-poll once without giving reason - but they can't change it to a name already belonging to a Finnish family. Finns take surnames seriously and many 'family names' have registered 'Kin Associations' built around them.
