The Land is the term used for the area of Land which encompases most of the story for the Chronicles of Thomas Covenant. It's Northern edge is called the North Plains, the South the Southron Wastes. The Land ends at the West by an area called Outer Earth and ends along the east at the shores of the Sunbirth Sea. All areas outside of this are not seen as part of the Land.
Below is a History of the Land and the rest of the World.
Era of Creation (Legend of the Wounded Rainbow)
The Creator and his children danced amongst the Heavens, and during this time the sky of the Land was entirely black, devoid of starlight. The Creator hammered and worked to create something new for his children who danced amongst the heavens, creating for them a Rainbow. Foul had marred his Rainbow creating a wound on its surface by adding spite to the Creator's mortar. The Creator's children danced gleefully across the rainbow, finding the wound, not understanding it and so danced through it in their innocence. The Creator in haste and anger sealed the wound, and trapped his children inside the Land and they became the stars in the sky after dancing across it.
Era of the King and Queen
During this time the King and Queen ruled from the city of Doriendor Corishev with love and beauty. At some point, a darkness came over the King's heart and he desired for more and more power. The Queen saw this and created an army to oppose him. With the help of Berek Halfhand and his aide Damelon Giantfriend her army fought for freedom from the King, whilst his army fought the Queen to protect their own slavery.
The Queen's army was crushed and Berek fled to Mount Thunder after fighting the King and become a half-hand. He prayed to the land and the Fire-Lions came to his aide, killing the King and his armies. During this time as well the Cavewights were not yet evil and crafted beautiful metals to trade with the people of the Land. The Viles at this time created the Demondim.
At some point the One Forest is felled causing the man-made ecological disaster resulting in the creation of the Southron Wastes, Doriendor Corishev could no longer sustain itself and so the people migrated north.
The Time Between
It is not exactly stated when the Giants first arrive in the Land however they are met by Damelon Giantfriend, who was alive during the Era of the King and Queen and Era of the Old Lords.
Era of the Old Lords
Berek Halfhand becomes the first of the Old Lords and the Unhomed are given Seareach by Damelon Giantfriend, and in return they build Revelstone. Damelon later names Rivenrock and finds the Blood of the Earth under Melenkurion Skyweir.
Kevin Landwaster is finally born, who rules for 1000 years. Lord Foul works his way into Kevin's Council and is ultimately discovered by Kevin causing battle throughout the Land. Kevin's armies falter and after the last battle at Kevin's Watch he meets Foul under Mount Thunder and invokes the Ritual of Desecration.
Kevin in this Era also gathers his Lore into the Seven Wards hoping to protect his knowledge should Foul be triumphant. The first Ward he bestows to the Unhomed.
Era of The Desecration
After the Ritual of Desecration, the land seems to have become devoid of almost all life. The people who had dwelt in Stonedowns fled to The Wastes and there survived through Rhadhamaerl lore. Some life did survive, as the Wraiths of Andelain are said to have been immune to the effects of the Desecration.
The Giants became forgotten by people, the few that had survived on a Giant ship hiding in Coercri. Presumably the Staff of Law was lost during this Era, Saltheart Foamfollower is also born during this time aboard a Giant ship.