Complex sentence: In Norse mythology, King Þrymr ("Thrymr ","Thrym ";"uproar") of the jotnar stole Mjollnir, Thor's hammer, to extort the gods into giving him Freyja as his wife.
Split into simpler sentences: In Norse mythology, Þrymr ("Thrymr ","Thrym ";"uproar") was king of the jotnar. In one legend, he stole Mjollnir, Thor's hammer, to extort the gods into giving him Freyja as his wife.