"Tékumel: Empire of the Petal Throne is a role playing game based upon the imaginary world created by Professor Muhammad Abd-el-Rahman Barker as a linguistic exercise.
"Barker was a Professor of Urdu and South Asian Studies at the University of Minnesota during the period when David Arneson, Gary Gygax and a handful of others were developing the first role-playing games in Minneapolis and Lake Geneva, Wisconsin. Barker tapped into this tradition and his childhood fantasies (very much like H. G. Wells did for his Little Wars) to explore and develop the Tékumel setting. His "Thursday Night Groups" were some of the first roleplaying sessions anywhere and provided what was, at the time, a unique, week-by-week development of the setting.
In 1975, Tactical Studies Rules, Inc., the publishers of Dungeons & Dragons, published the Tékumel fantasy setting as a standalone game under the title of The Empire of the Petal Throne (a synonym for the Tsolyáni Empire). It brought a level of detail and quality to the campaign setting which had previously been unknown in the RPG industry, and could be considered a turning point away from the tactical roots of RPGs.
Tékumel has spawned four professionally-published roleplaying games over the course of the years:
* Empire of the Petal Throne, published in 1976 by TSR, Inc.
* Swords & Glory, published in 1983 by Gamescience.
* Gardasiyal: Adventures in Tekumel, published in 1994 by Theater of the Mind Enterprises.
* Tekumel: Empire of the Petal Throne, published in 2005 by Guardians of Order."
Source: Wikipedia, "Tékumel", available under the CC-BY-SA License.