In what year did Captain Cook's great voyage to the south pacific begin?

please help it's for school. Bessie xx

1777

Captain James Cook Biography.

On July 30th 1768 Cook received his secret instructions from the Admiralty and made ready to sail to the Pacific to observe the Transit of Venus and to search for Terra australis incognita, the Great Southern Continent.

(It wasn't 1777, as stated above, because Capt Cook, sailing on the Endeavour, found my homeland Australia in 1770.)