After overcoming the menace of Mara, and continuing with great diligence for the whole night, the would-be Buddha gained the all-knowing wisdom, sabbanuta-nana when grey dawn loomed over the eastern horizon.
As soon as he gained the all-knowing wisdom and thus became the Buddha, the earth shook with a great force by way of hailing the great event.
Concepts and terminology:
Sabbanuta-Nana (Sab-ba-nu-ta Nya-na) : A form of omniscience possessed by all Buddhas. Links: Wikipedia
Mara (Ma-ra): An evil deva. The lord of misfortune, destruction and death. Links: Wikipedia