In 2009, after a public appeal, the British Library purchased a manuscript ‘Booke’, which Captain Narbrough bought in 1666 and into which he subsequently entered his journals of his voyages and correspondence relating to them. The ‘Booke’ contains his own fair copy of the journal of his voyage through the Strait of Magellan and north to Valdivia in the Sweepstakes, 1669-1671. This is published here for the first time, together with an incomplete and somewhat different copy of the journal, held in the Bodleian Library, which was made for him by a clerk after he returned to England, and which was partially published in 1694. Both versions of the journal together with previously unpublished records made by members of his company, as well as reproductions of the charts which Narbrough relied on and those he produced, are printed here. Narbrough's mission was to carry out a passenger who referred to himself as Don Carlos Enriques and who claimed to have expert knowledge of Peru and Chile, and contacts with disaffected colonists and indigenous peoples. Don Carlos's written proposals to King Charles II and his ministers, only recently discovered, are here translated from Spanish, and give a clear sense of the character, if not the real identity, of an adventurer, who gave the authorities in England, Chile and Peru totally different and changing stories about his status and the purpose of the voyage. Narbrough's conduct of the voyage has been criticized by later authors who have focussed on his inability recover four of his ship’s company from detention in Valdivia and the lack of tangible results, in the form of trade or contacts with indigenous groups. The more complete story provided here shows that Narbrough carried out his ambiguous orders to the letter. His chart of the Strait of Magellan remained the principal chart of the area for the next century. King Charles II and James, Duke of York, both recognized his abilities. He was rapidly re-employed in naval service, subsequently knighted, and rose to become a Commissioner of the Navy and Commander in Chief in the Mediterranean.