Draconic Goetia is a ritual that allows you to summon dragons and revive them back into the world. The most notable quest relating to this is Draconic Revival.
The components needed for the ritual are:
One seeking to perform the ritual will need to place the Divine Blood onto The Cold Stone and activate The Cradlestone speaking the phrase "The Dragons are extinct no more" in Draconic Tongue.
Doing this will consume the divine blood to create a dragon egg, rebirthing Kal, the eldest dragon.
Kal will take one week to hatch and a further two weeks to grow to full size. Once Kal has grown to full size, she will lay four eggs, one for each element. If left somewhere private (eg in the Keep of Kal) the Dragons will repopulate on their own.