The wood-elf king

This is Thranduil, king of the wood-elves of
Mirkwood. He is one of the leaders who brings an
army to the Battle of the Five Armies. He also
held the dwarves in one of his dungeons but later became friends with them. He has a fortress in the caves near Mirkwood.
"This was the bridge that led across the river to the
elf king's doors."
This is describing the path to his palace.