The Ancients are one of the four great races, and are those who created the Stargate. Though they physiologically seem human, they can heal wounds or disease by applying their hands. this however is not an ability of their body, but of their mind: when Jack was under the influence of their knowledge, he was able to heal [[enc/Bra'tac]] in the same way.

Their speach is related to the post-Medieval Latin. Besides, the Romans (yes, they spoke Latin, but that is not all) were taught to build roads by the gods known as "the ancient ones". One may draw a parallel between these roads and the Stargates.

The Ancients were indeed present on Earth several million years ago, and, being called the "Alterans", they built the Stargate network SG-1 used for almost eleven years. However, they suffered a plague and left Earth between five and ten million years ago, aboard their flying city, Atlantis, which headed to the Pegasus galaxy, leaving only Ayiana and an outpost behind. This was the outpost Jack used to protect Earth from Anubis' attack.

In the Pegasus galaxy, they built a new Stargate network to meet new people and develop friendship and trade with them. But they finally awoke the most powerful enemy they had ever met: the Wraith. Having no other solution, they fled back to Earth ten thousand years ago, sinking the city into the ocean and making it to sleep, in the hope they could later come back.

Later, the Ancients gave their mortal coil up and reached a superior plane of existence, where they are sheer energy. They call Ascension the process that enables someone to go from our plane to theirs. Once one is ascended, they shall no longer interfere with our plane of existence, but some have not respected this law (for example Oma Desala and Orlin), and among them several where punished, as Daniel who was sent back to our plane.

The Ancients calculate in base 8, whereas we usually use base 10.