King Olaf Tryggvason raided England in the late 900s. With the loot he garnered, he constructed the Long Serpent, perhaps the largest Norse ship ever constructed, a vessel supposedly over 120 ft. long that could carry 500 men. 

"The ship was a dragon...but this ship was far larger, and more carefully put together in all her parts. The king called this ship the Long Serpent... The Long Serpent had thirty-four benches for rowers. The head and the arched tail were both gilt, and the bulwarks were as high as in sea-going ships. This ship was the best and most costly ship ever made in Norway."

-- Snorri Sturluson, Heimskringla