The realm of Thingol in Beleriand, Doriath was one of the greatest
of the Elf-kingdoms. It was sacked by Dwarves after the death of
Thingol. After which Dior Eluchíl, his grandson became king. Dior
was slain by the sons of Fëanor and so ended the realm of Doriath.
Within Doriath was Mengroth, the underground palace.