Earth

Earth (aka Other World by people of Daventry) is the name of a planet located in the Milky Way Galaxy of the Universe. The world revolves around the Sun, and shares the solar system with nine other planets including Jupiter. Constellations such as Leo can be seen in its night skies. It is circled by the Moon. Long ago, Earth was home to kingdoms such as Daventry, Serenia, and Llewdor.

History
Daventry, Serenia, Llewdor and other such lands were kingdoms that existed long, long ago in earth's past. As time progressed technology began to displace magic. Mythic creatures and magic users began to be persecuted by the human race, and their lands dwindled as civilization grew. Running out of places to hide, various mythic races and magic wielders used magic to withdraw across the multiverse to the ancient kingdoms to avoid extinction. They knew the passage would be one way, and there would be no return to their own kingdoms. The first withdrawal occured hundreds of thousands of years ago, lead by the great Chrispinophur to the land of Serenia. More withdrawals occured around the world for various reasons from places such as Greece, Egypt, and Innsmouth.

As time passed, people began to call the places they came from the Other World (though many continued to call the world, Earth). They had no name for world they moved into. In time the people learned how to contact the present world or ancient kingdoms through dreams and artifacts such as the Eye Between the Worlds. People such as Roberta Williams dreamt of Daventry and Derek Karlavaegen could send messages to the present world. These methods linked the ancient Daventry to 20th century earth causing them to overlap. This communication between the worlds lead to the creation of the King's Quest Game series (last known contact occured circa 1998 for the creation of King's Quest: Mask of Eternity). In time the bond became stronger in such that the Great Dreamer Roberta was able to have impact on the ancient kingdoms allowing her to reshape them.

Lands

 * Daventry
 * Kolyma
 * Llewdor
 * Tamir
 * Serenia
 * Green Isles
 * Land of the Clouds
 * Land of the Leprechauns
 * The Swamp
 * Underground Realm of the Gnomes
 * Barren Region
 * Frozen Reaches
 * Paradise Lost

Other lands

 * Egypt
 * Greece
 * Rome
 * Troy
 * Israel
 * India
 * Assyria
 * Babylon
 * China
 * Japan
 * North America
 * England
 * Ireland
 * North Pole
 * Island of Man
 * Middle East
 * Europe

Behind the scenes
"Well, ya, King's Quest is on earth. Daventry is very old city from a long time ago. It's in ruins now and people aren't quite sure exactly where it used to be. There are some archaeologists searching through the ruins, they think they know its Daventry. But its somewhere on Earth.'" -Roberta Williams, Talkspot Interview, part 1 (1:20:40 to 1:59:58)

The name of the world as "earth", is mentioned several times throughout the King's Quest series within the manuals and within the games KQ1SCI, KQ2 , KQ3 , KQ6 , KQ8

Even Eldritch is described as being on an 'earthly plane' in KQ7. In the King's Quest Companion, Eldritch is in yet another parallel world from even Daventry. At the end of the game, Edgar, Titania and Oberon, even say that Rosella was lured into another world.

In KQC, the Druids describe Alexander as a 'man of Earth'.

The novel trilogy hints at the world being earth as well.

Derek suggests that the 'contempory time' in Daventry, and time on earth are at different times. This may support the idea that some kind of time travel exists between both worlds.