Indo-European religion in the context of "Trundholm sun chariot"

Germanic paganism or Germanic religion was the traditional, culturally significant religion of the Germanic peoples. With a chronological range of at least one thousand years in an area covering Scandinavia, the British Isles, modern Germany, the Netherlands, and at times other parts of Europe, the beliefs and practices of Germanic paganism varied. Scholars typically assume some degree of continuity between the beliefs and practices of the Roman era and those found in Norse paganism, as well as between Germanic religion and reconstructed Indo-European religion and post-conversion folklore, though the precise degree and details of this continuity are subjects of debate. Germanic religion was influenced by neighboring cultures, including that of the Celts, the Romans, and, later, by Christianity. Very few sources exist that were written by pagan adherents themselves; instead, most were written by outsiders and can thus present problems for reconstructing authentic Germanic beliefs and practices.

Some basic aspects of Germanic belief can be reconstructed, including the existence of one or more origin myths, the existence of a myth of the end of the world, a general belief in the inhabited world being a "middle-earth", as well as some aspects of belief in fate and the afterlife. The Germanic peoples believed in a multitude of gods, and in other supernatural beings such as jötnar (often glossed as giants), dwarfs, elves, and dragons. Roman-era sources, using Roman names, mention several important male gods, as well as several goddesses such as Nerthus and the matronae. Early medieval sources identify a pantheon consisting of the gods *Wodanaz (Odin), *Thunraz (Thor), *Tiwaz (Tyr), and *Frijjō (Frigg), as well as numerous other gods, many of whom are only attested from Norse sources (see Proto-Germanic folklore).

Ancient Celtic religion, commonly known as Celtic paganism, was the religion of the ancient Celtic peoples of Europe. Because there are no extant native records of their beliefs, evidence about their religion is gleaned from archaeology, Greco-Roman accounts (some of them hostile and probably not well-informed), and literature from the early Christian period. Celtic paganism was one of a larger group of polytheistic Indo-European religions of Iron Age Europe.

While the specific deities worshipped varied by region and over time, underlying this were broad similarities in both deities and "a basic religious homogeneity" among the Celtic peoples. Widely worshipped Celtic gods included Lugus, Toutatis, Taranis, Cernunnos, Epona, Maponos, Belenos, and Sucellos. Sacred springs were often associated with Celtic healing deities. Triplicity is a common theme, with a number of deities seen as threefold, for example the Three Mothers.

Proto-Indo-Iranian religion was the religion of the Indo-Iranian peoples and includes topics such as the mythology, legendry, folk tales, and folk beliefs of early Indo-Iranian culture. Reconstructed concepts include the universal force *Hṛta- (Sanskrit rta, Avestan asha), the sacred plant and drink *sawHma- (Sanskrit Soma, Avestan Haoma) and gods of social order such as *mitra- (Sanskrit Mitra, Avestan and Old Persian Mithra, Miϑra) and *bʰaga- (Sanskrit Bhaga, Avestan and Old Persian Baga). Proto-Indo-Iranian religion is an archaic offshoot of Indo-European religion.

In historical Indo-European religion, the concept of an otherworld, also known as an otherside, is reconstructed in comparative mythology. Its name is a calque of orbis alius (Latin for "other world/side"), a term used by Lucan in his description of the Celtic Otherworld.

Comparable religious, mythological or metaphysical concepts, such as a realm of supernatural beings and a realm of the dead, are found in cultures throughout the world. Spirits are thought to travel between worlds or layers of existence in such traditions, usually along an axis such as a giant tree, a tent pole, a river, a rope or mountains.

The gods and goddesses of the pre-Christian Celtic peoples are known from a variety of sources, including ancient places of worship, statues, engravings, cult objects, and place or personal names. The ancient Celts appear to have had a pantheon of deities comparable to others in Indo-European religion, each linked to aspects of life and the natural world. By a process of syncretism, after the Roman conquest of Celtic areas, most of these became associated with their Roman equivalents, and their worship continued until Christianization. Epona was an exception and retained without association with any Roman deity. Pre-Roman Celtic art produced few images of deities, and these are hard to identify, lacking inscriptions, but in the post-conquest period many more images were made, some with inscriptions naming the deity. Most of the specific information we have therefore comes from Latin writers and the archaeology of the post-conquest period. More tentatively, links can be made between ancient Celtic deities and figures in early medieval Irish and Welsh literature, although all these works were produced well after Christianization.

The locus classicus for the Celtic gods of Gaul is the passage in Julius Caesar's Commentarii de Bello Gallico (The Gallic War, 52–51 BC) in which he names six of them, together with their functions. He says that Mercury was the most honoured of all the deities and many images of him were to be found. Mercury was regarded as the inventor of all the arts, the patron of travellers and of merchants, and the most powerful deity in matters of commerce and gain. After him, the Gauls honoured Apollo, who drove away diseases, Mars, who controlled war, Jupiter, who ruled the heavens, and Minerva, who promoted handicrafts. He adds that the Gauls regarded a god he likened to Dis Pater as their ancestor.

The world tree is a motif present in several religions and mythologies, particularly Indo-European, Siberian, and Native American religions. The world tree is represented as a colossal tree which supports the heavens, thereby connecting the heavens, the terrestrial world, and, through its roots, the underworld. It may also be strongly connected to the motif of the tree of life, but it is the source of wisdom of the ages.

Specific world trees include Égig érő fa in Hungarian mythology, Ağaç Ana in Turkic mythology, Kenac' Car in Armenian mythology, Modun in Mongol mythology, Yggdrasil in Norse mythology, Irminsul in Germanic mythology, the oak in Slavic, Finnish and Baltic, Jianmu (Chinese: 建木; pinyin: jiànmù) in Chinese mythology, and in Hindu mythology the Ashvattha (a Ficus religiosa).