Himilco was the first recorded Carthaginian captain to make a voyage into the North Atlantic, but unlike Hanno’s voyage, Himilco's exploration to the north did not result in any colonies being established. Pliny the Elder records that Himilco voyaged for four months along the Tartessian trade route. According to Pliny, Himilco, his ship and crew were endangered by calm waters, shoals, tangling seaweed and sea-monsters. The Roman author Avenius relates that Himilco sighted Brittany, but does not state whether he continued on to the British Isles. The date of Himilco's voyage can be approximated between 480 and 500 BCE. His discoveries gave the Phoenicians some control of the tin trade as far as Brittany, but dissatisfied with the results, they later tried to establish an overland route from Spain to the tin mines. They eventually established a trade route to the “Tin Islands,” and it is possible they mistook the tin-producing Cornish peninsula for islands.