Associated with: Ancient Germanic and Old Norse belief systems
Also known as: Þunor, Donar and 14 other names, most frequently Atli ("the terrible"), Einridi ("the one who rides alone"), Hloridi ("the loud rider"), Rym ("noise") and Vingthor
Earliest recorded mention: Unknown, but before Tiberius' conquest of the Germanic tribes in 1-4 CE
Major texts: Poetic Edda, Prose Edda
I could not help but wonder, when I saw (and thoroughly enjoyed) Thor at the movies this summer, how modern Christians would react to a movie that portrayed Jesus as a Marvel superhero. But then, Jesus didn't make a habit of smiting his enemies, and many of the stories of Thor in the Eddas would fit perfectly well in a comic book.
Thor was, of course, the god of thunder, and is the source of the name Thursday. He was the son of Odin, the Allfather, and of Jord, who personifies the Earth Primeval. Thor's hammer Mjollnir throws lightning, while thunder comes from Thor's chariot, drawn by the goats Tanngrisnir and Tanngnost. He has a red beard and red hair, and many children born of several different goddesses. He was the strongest of the gods, with his strength doubled by a magic belt, Megingjard.
The Roman historian Tacitus, describing the religious practices of the Germans, associated Thor with the Roman god Hercules, and noted that Thor did not require human sacrifices, while Odin did. This willingness to settle for animals instead of human was one element that made Thor the most popular of all the Norse gods, especially once Christian missionaries reached the tribes of Germany and Scandinavia. The worship of Thor survived well past the official Christianization of Norway; it was easy to disguise Thor's hammer symbol as a cross, and archeologists have found quite a few of these amulets. The swastika was also a symbol of Thor, especially popular with women, before Adolf Hitler adapted it to his own uses. The Grimm brothers recorded references to Thor in the fairy tales they collected from Germans in the 19th century.
At the end of the universe — Ragnarok, in Norse mythology, and the Gotterdammerung, in German — prophecies say that Thor will battle Jormungandr, the Midgard Serpent, who will rise up and cause the seas to flood and boil. Jormungandr will poison the earth and soil before Thor finally kills him, but Thor himself will be poisoned and die as well. The worlds will burn, the earth will sink into the sea, but from this devastation a new world will emerge. Two human survivors, Lif and Lifthrasir, will start a new civilization.
Scandinavia and Iceland, in particular, are harsh climates subject to almost every extreme natural phenomenon: volcanoes, earthquakes, blizzards, terrible storms, floods, droughts, etc. The prophecies of Ragnarok explained these phenomena and offered the promise that humanity would survive them, in some form, even if the gods did not. It's pretty radical, if you think about it: a religion that promises that humanity will outlive its gods. It's a worldview with deep implications for German history, in particular, inspiring (among others) Nietzsche, Wagner and Hitler himself.