Thranduil

Thranduil was a wood elf who was the king of Greenwood/Mirkwood and the father of Legolas. He fought in the War of the Last Alliance. Sauron was then defeated in 3441 of the Second Age. In 1050 of the Third Age Sauron cast a shadow on the Greenwood and the city would then be called Mirkwood. Spiders, orcs, and other evil creatures came to dwell there. Thranduil and his people built halls in underground caverns. Thranduil captured Thorin Oakenshield and took the elvish sword Orcrist from him. His other dwarf companions were captured later, but Bilbo Baggins escaped with the Ring. Thranduil then set out for Lonely Mountain and met Bard on the way. They came across Thorin on the way to the mountain and Thorin was going to start a war with Thranduil for imprisoning him but Bilbo Baggins gave him the Arkenstone and Thorin sent for his cousin, Dain Ironfoot. Then orcs and wargs came down from the Misty Mountains and they fought together in the Battle of the Five Armies. They were losing until eagles came and helped them win. Thranduil would later hold Gollum captive until he escaped because of orcs. Thranduil would get help from Celeborn who lifted the shadow on Mirkwood. The wood elves dwelled north of the mountains in the forest untroubled for many years.

Source: "Elves of Middle Earth" http://www.tuckborough.net/elves.html