Created by John Boome and Gil Kane in Green Lantern Vol.2 #1 (July 1960) they were modeled after the then Prime Minister of Israel, David Ben-Gurion.
The Maltusians were one of the earliest sentient lifeforms in the universe. They were great experimenters and thinkers, even experimenting on some of the lizard-like creatures around them, creating the race now known as the Psions.
When a persistent Maltusian scientist known as Krona (Entropy) created a experiment capable of viewing the beginning of time, a disaster occured that created the Multiverse and the Anti-Matter Universe of Qward.
After this, the Maltusians left their homeworld and settled on Oa, in the "center of the universe", and feeling as they were all responsible for the devstation Krona had caused, wanted to contain the evil of the universe that was created. But, due to disagreements amongst them, their race split into 3 factions, one becoming what we now know as the Guardians, who want to contain evil, one wanting to eliminate evil, known now as the Controllers, and the Maltusian female counterparts who disagreed with both sides and decided there was no need to be involved in either. Parted ways and became the Zamarons.
Later, the Guardians created the Green Lantern Corps to protect the Universe from evil. While the Controllers created the Darkstars, and the Zamarons created Star Sapphire.