In most ancient cultures the belief in spirits was common, from the beginning of time humans have believed in invisible supernatural beings who could interact with the physical world, especially nature spirits were often worshipped.
Like most other ancient cultures the Germans believed that impressive natural phenomenons like big stones, trees, rivers, and mountains were inhabited by spirits or divine powers, this spirits are invisible and were seen as living beings that consist of energy instead of flesh and bone and who can use their powers to aid or oppose human developements.
The Proto-Germanic word for ghost/spirit is "gaistaz", a word that is also connected to earth and untamed nature, an old-fashioned Dutch word for wild unexplored terrain is "geestgronden" (spiritgrounds), while the Dutch word for spirit is "geest", there may also be a connection to Proto-Germanic "gastiz" (guest).
Spirits were very important in the Germanic religion and they received even more worship than the gods, especially Alfen, Landwights, and Disen were important while for instance the Nornen and Valkyries weren't worshipped at all because they only perform their tasks and can't be influenced with offerings.
The belief in spirits is very old and they appear in many cultures, nowadays we tend to see Spirits as evil ghosts or other scary things but our ancestors saw them as natural appearances who could do both good and evil, just like ourselves.
The people believed in different forms of spirits;
Alfen and related spirits:
Alfen: the Alfen or Alfar (Elves) are also known as white Alfen, they are common nature spirits and represent uncultivated nature and live in forests and lakes, they are associated with butterflies and other beautiful creatures and according to some sources they can fly and are transparant, their leader is the god Frey and one of their kings is Alberich (from Proto-Germanic "Albireikaz", which means "Ruler of the Alfen"), Shakespeare's "Midsummernightsdream" is inspired on this character as well as Weber's opera "Oberon", which is the French name for Alberich.
The Proto-Germanic word for Alf is "Albiz", a word that also means "white", the name of the river Elbe is also believed to be derived from this word and probably means something like "white river".
In Dutch the Alfen were called Alven, Alfen, Sommeltjes (?), Guurkens (?), Auvers (Alfen), Hansjoppen (may be derived from "hansop", which is some sort of overall/boilersuit), Aardgeesten (Earth-Spirits), Aardmannetjes (Little Earthmen), or Alvermannekens (little Alfen-men), and in German the word Alben or Erdmännchen (little Earthmen) was used.
Negative versions of the Alfen are the Svartalfar/Swartalfen (Black-Elves), this evil spirits are also associated with Dwarves.
The Alfen are associated with nature and during certain times in the year they dance around in circles to fertilize the earth, they mostly do this on hills or in open spaces in forests, on the ground where they have danced a fairy ring often appears.
Sometimes the Alfen replace human children with their own, this children were called "Changelings" (English), "Wisselkinderen / Elfenkinderen" (Dutch), or "Wechselkinder / Wechselbälger / Elfenkinder" (German) and they can be recognized by their dreamy behaviour and their lack of social interaction, this belief was probably based on autistic children whose mothers interpreted their odd behaviour as that of another being, in later periods the Changelings were believed to be the children of Black Elves (Svartalfar), Trolls, Dwarves, or Kabouters, and they were depicted as evil beings with disfigurements who ate so much that they made their parents poor, after the Christianization the Changelings even became children of witches, White Women, or Satan who were sent to harm humans, because of this children who were believed to be Changelings were often killed by their parents.
Landwights: other types of spirits that are closely related to the Alfen (or are probably even the same) are the Landwights (or Landvættir in Old Norse), this are nature spirits who are connected to a certain place or object, they often help humans and are very shy and easy to scare away; during the Christianization of northern Europe priests often sprinkeled holy water in forests or other places in nature to get rid of the Landwights, though it often happened that some local people quickly invited them back in by leaving milk or other offerings because they were afraid to lose their support.
The Landwights are probably connected to the Wanen gods and have very old origins, most Indo-European cultures knew nature spirits in some form or another and also the pre-Indo-European cultures in Europe are believed to have worshipped them, a good example of this common belief in land-spirits are the Sidhe from Celtic mythology; this are land spirits who are believed to inhabit hills and old stone buildings and have many similarities with the Germanic Landwights.
Landwights are often connected to a certain place, object, or tree, especially in the case of a living being like a tree the spirit can not leave and will die when the tree dies, in the case of a non-living object like a stone, a waterfall, or a cliff the spirit will be able to leave and choose a new home.
A good example of the close relationship between the people and the Landwights is the first heathen lawbook of Iceland from 930AD, which contains the rule that every ship carrying a dragon's head should remove this as soon as it approaches the coast of Iceland so that it wouldn't scare the Landwights.
During the colonization of Iceland people were also especially careful and respectful of the Landwights who were already living in the land, the offerings and respect of the people were also rewarded by them though:
In the 10th century the Danish king Harald "Bluetooth" Gormssom wanted to conquer Iceland and for that purpose he sent a wizard to explore the island for his invasion force.
But when the wizard arrived in Iceland was chased away by the Landwights who changed into a dragon with an army of monsters, a huge eagle with an army of birds, a giant bull, and a giant with an army of giants.
Because of this the Danish king decided not to invade Iceland, the heraldic symbol of Iceland still carries a giant, bull, eagle, and a dragon as a reminder of this event.
Waterwights: a good example of Water spirits are the Rhinemaidens who mainly appear in the legends about Siegfried, this maidens have much in common with the Greek Nymphs and live in rivers and lakes after which they were often named, for instance the Rhinemaidens were believed to live in the river Rhine (which was called "Rinaz" by the Germans), the river Elbe (Germanic name: *Albiz) also has a connection to spirits and may have something to do with the Alfen, the river Weser (Germanic name: Wisura) may be connected to "wisulon" (making something miserable), and the Neckar river is connected to the Nekar/Nixen.
Many other rivers and lakes also had their own beings attached to them, most of those were spirits or maidens like the ones from the Rhine, sometimes a "lady of the lake" was worshipped or a being that was named after the river or lake, this type of beings are related to the Alfen and the Landwights and may have originally represented Waterwights.
During summer the Rhinemaidens retreat to the forests where they are believed to dance around trees and have fun.
The Slavs believed in Rusalka's which are the spirits of young girls who have drowned, the Rusalka also live in rivers and lakes and also retreat into the forests during summer.
Housewights: a Housewight is a guardian spirit who lives in the house and protects the family, if the family moves to another house the Housewight sometimes decides to stay with the family and moves with them to the new house.
Housewights are related to the Landwights (who can also inhabit houses) and when a House Wight is angry he can show that by using his forces to make noise and throw objects through the house like a poltergeist, which is a German word meaning something like "rumbling-ghost", the Dutch word is "klopgeest", which means "knocking-ghost".
Kobolden/Kabouters: the Kobold (German) or Kabouter (Dutch) is a Housewight who lives under the roof of a house or behind the fireplace, they are helpful beings and at night they come out of their hiding places and perform jobs in the kitchen, stable, or shed; as a reward the people sometimes left milk, cream, or soup for them.
In the Netherlands we still use sayings like "Get to work, because the Kabouters won't do it for you!", on a ship the Kabouter is called "Klabouter"; at night they repair the ropes and sails of the ship and when the ship is going to sink the klabouter shows himself to the captain to warn him for the upcoming disaster.
In the Middle Ages the Kabouter was very important to the people; he was helpful, warned for upcoming events, put things in order, and loved mocking everybody, nowadays Kabouters are seen as small men with beards and pointy heads but this was mainly caused by the small wooden Kabouter idols that the people kept in their houses and the modern association with Dwarves, originally the Kabouters were seen as helpful spirits; Kabouters or Kobolden are only known in Germany and the Benelux (Belgium/Netherlands/Luxembourg) and are probably a later adaptation of Housewights, in the Netherlands there are also stories of Alfen who help people and clean their houses, just like the Kabouters and Kobolden.
Gnomes: Gnomes are earthspirits who guard every mine and quarry where ore is present, there are both good and evil Gnomes, in many folktales the Alfen perform the same tasks so the Gnomes are probably later adaptations of the Alfen.
Corn spirits: the Cornspirit (German: Korngeist, Dutch: Korengeest) is a spirit who inhabits a cornfield, it dies during harvest and is reborn when the replanted seeds come up again.
In the Dutch province of Groningen people once believed in the Roggemoeder (Rye-mother), who was later also used to frighten children with.
A similar character is the Korenschrik (Cornfright), who is an old lady who lives in the corn, her name was used to scare children so they would stay out of the corn and wouldn't damage it.
The folklore of Gelderland also mentions a Heggemoeder ("Hedge-mother"), who lives in hazel bushes and sneaks into houses at night to harm women, especially women who have just gotten a baby.
One of the ways to protect yourself against the Heggemoeder is to place your shoes with the heels towards the bed, the same protection also helped against the Mare.
The corn spirits are probably related to Alfen or fertility goddesses, many of them show a later demonization to make the people afraid of them.
Black Alfen (Swartalfen): the black Alf is an evil version of the white Alf, they are almost the same as the Alfen and also have the same characteristics but instead of helping humans and caring for nature they try to destroy everything, they were believed to be transparent though sometimes also have a black mist around them, in later times they were believed to work for Satan but originally they were independant spirits who just liked being evil.
Nekars/Nixen: the Nekar (Proto-Germanic *nikwis = "water spirit"), also known as Nixe (German), Nekker/Nikker (Dutch), Nihhus (Old High German), Nicor (Anglo-Saxon), Nykur (Old Norse), or Nökke (Modern Scandinavian), is an evil black water spirit who is probably connected to the black Alf, they can change into various forms, often a horse or a black demon, and some of them demand a human sacrifice each year.
It is believed that the Neckar river in Germany is named after them and in the Beowulf saga a watermonster is mentioned as the mother of Grendel.
In later times the word "Nekar" was also used for other types of demons and evil spirits, in Dutch folklore they changed into Boezehapperts (derived from "boze happers" = evil biters) who were believed to lurk in the reed to drag people into the water and drown them.
There is also a theory stating that the word "nigger", an insulting word for people of African origin, is derived from the nekar too, and was originally applied to Africans because of their dark skincolour.
In some old Dutch children songs the word "nikker" is used to refer to Africans, most these songs date from a time when the word only referred to dark skincolour and may have had no insulting intention, but these days the word has a very negative meaning and is considered highly disrespectful towards Africans, the songs themselves were either removed from songbooks or adapted to make them less offensive.
Mara's: the Mara is an evil spirit that causes sleeping people to have nightmares, the word "mare" in "nightmare" probably originates from it, the Dutch word for "nightmare" is "nachtmerrie", the Swedish and Icelandic words are both "mara", and the German word is "Alptraum", which may suggest a connection to the black Alfen.
Dwarves:
The Dwarves are small creatures with evil tendencies who are probably related to the Svartalfar, they live underground and can make themselves invisible, they were also believed to be excellent smiths.
Mermaids:
The Mermaid may be a later variation of the Water Wight though according to most legends Mermaids and Mermen are the children of Ægir and Ran, they are half human and half fish and they are believed to foresee certain events (see: magic), a Mermaid sometimes marries to a human but has to leave her partner again when he sees her naked or asks for her origins, in later times the Mermaid was turned into an evil being that sinks ships and is associated with Satan, but that is a later Christian influence.
Druden:
In Germany there was the belief in Druden (Proto-Germanic "Þruþijiz"=powers), some theories state that the Druden are female spirits who may be related to the Walküren but a better explanation is that they are evil spirits of the dead (Perchten) who take part in the Wild Hunt, this belief is one of the oldest aspects of German folklore and has been derived from a common Germanic belief, after the Christianization the Druden were seen as witches and many parents used their name to chase naughty children to bed, originally they were evil souls that had escaped from the world of the dead to roam the human world.
Ancestral spirits:
Ancestors: ancestor worship was common in most ancient cultures and the Germans did not form an exception; dead relatives were asked for advice and children were often named after a grandmother or great-grandfather to allow their soul to be reborn into the new child, just like Christians nowadays burn a candle for a dead relative the Germans erected a stone or altar for their dead relative to honour him or her and they also visited their graves or the place where there ashes was dispersed to speak to them or ask advice.
Disen / Dísir / Idisi: the Disen (Proto-Germanic: Disiz, pleural: Disijiz) are guardian spirits who were associated with ancestors and fertility, most of them are spirits of dead female relatives who protect the family and/or individuals within that family.
The worship of "Matrones" that is mentioned in Roman sources was probably a cult for the Disen too, they were especially honoured during Winter Nights (see: holidays).
According to Icelandic legends there was in the year 1000 a tribal chief named Hall of Sida and his son Þidrandi who converted to Christianity, not long after that Þidrandi was killed by nine Disen riding on horseback in black clothing.
In most legends the Disen are mentioned as friendly and helpful spirits though, and they often appear to help someone through a difficult period or warn them for future events.
Wiedergänger / Wedergangers / Gengangers:
When a person dies he or she is dead and never returns (unless by reincarnation), however, some of them do return and this people were called Wiedergänger (Germany), Wedergangers (Dutch), or Gengangers (Scandinavia), which means "back-comers", a dead person can become a wiedergänger when he is evil, dies an unnatural death, or simply because he does not know that he is dead.
The Wiedergänger can come out of the ground and disappear into it again, some of the more evil Wiedergängers also kill humans and animals, the bodies of their victims do not show any wounds but simply turn blue and stiff.
A legend from the Dutch province of Gelderland tells about a knight who falls in battle but returns as a "wederganger" to take his wife with him into the earth.
White Women:
White Women are probably nature spirits or souls of wise women who have died, they were later turned into witches but their original character was very positive, more information about them can be found here.
Guardian spirits:
Fulgjoz: the Fulgjo (Proto-Germanic), Fylgja (Old Norse), or Folgôn (Old Saxon) all mean "follower" or "fetch", the Fulgjo is a personal guardian spirit, sometimes the Fulgjo takes an animal form though it can also be an ancestor or another spirit, the Fulgjo is the heathen equivalent of the Christian Guardian Angel.
Most people were believed to have at least one Fulgjo though it is also possible to have multiple Fulgjoz, a Fulgjo mostly appears in someone's dreams in which he gives advice or hints, they were also believed to test someone's personality by placing them in dreams about challenging situations.
The Fulgjo also represents the characteristics of a person and when that person dies he will be awaited by his Fulgjo who guides him to the Afterlife, it is believed that the doppelgänger legends are also connected to them.
A person could also allow his Fulgjo to take over his body, since most Fulgjoz often take an animal form it may be possible that this is where the Berserkr, Ulfheiðr, and Werewolf myths come from; by releasing the "animal inside" a person can take over that animal's abilities.
Hamingja: Hamingja (Old Norse) is not really a spirit but a form of energy that brings luck to a person, it is a part of the soul and it is also connected to the Fulgjo, in some people it is stronger than in others, Hamingja is inheritable and can be passed on from generation to generation, it is an abstract concept that probably represents a person's lifeforce or willpower.
Individual spirits:
Eckhart: this is a being from Medieval German folklore who is also known as Eckart or Ekkehart, he is a good spirit who sits at the entrance of a hill to warn the people for the wild followers of Holda; this aspect is derived from the Wild Hunt belief and is very similar to Berchta and her Perchten, he carries a white staff and appears in the legends of Dietrich von Bern and Tannhäuser.
Since Eckhart only appears in stories from the Middle Ages he is probably not of old origin but rather a later Medieval "invention".
Rübezahl: in German folklore this is a mountainspirit and the lord of the German Riesengebirge.
He was depicted as a Dwarf, Hunter, or Giant and may be related to the Slavonic Leshy spirit, though he also has similarities with the god Wodan.
Ellekonge: the name "Ellekonge" is a corruption of Danish "Elverkonge" (Elven-king), the Ellekonge is an evil spirit who steals human children at night, its origins are not entirely clear but it may be possible that the Ellekonge is based on an old heathen legend, though he is more likely to be a later invention since Elves were originally considered to be good beings.
In the 18th century the Ellekonge was adopted into German literature by Herder and Goethe, who named him "Erlkönig".
