Chaturanga is the earliest known version of chess. It originated in India during the Gupta Empire, before the 6th C. AD. The name Chaturanga comes from Sanskrit (catuḥ: "four"; anga: "arm"), meaning "having four parts," referring to the four arms of the Indian military: 1) Chariots, 2) Cavalry, 3) Elephants, and 4) Infantry.

Instead of a Queen, Chaturanga has a Counsellor piece, which was relatively weak, being only able to move one square diagonally. Pawns did not have the option of advancing two squares on their first move, and promote to Counsellor if reaching the back rank. Either White or Black could move first.

The one step forward or one step in any diagonal direction movement of the Elephant in Chaturanga is described C. 1030 by Biruni in his book India.

< 6th C. AD

Chaturaji, meaning "four kings," is a four player chess-like game from India that originally was a game of chance. There's some conjecture that a version of Chaturaji may have been a predecessor of Chaturanga, and hence the ancestor of Modern Chess (Cox–Forbes theory). However, modern scholars generally agree that Chaturanga was first, though we don't know for sure.

The Boat piece moves two squares diagonally, while jumping over the first square. Boats and Pawns are considered minor and may not capture Kings. Pawns promote to the piece that starts on the same file (or rank) of the promotion square. The Elephant moves like a modern Rook.

Chaturaji alludes to a time when India was divided into many rival kingdoms and is often played in a team format.

< 7th C. AD

The movement of the Elephant of Chaturanga changed to moving two squares diagonally, while jumping over the first square, and the game became known as Shatranj, first appearing in Persia around the 7th C. AD.

The name Shatranj comes from Persian (shat: "100"; anga: "worries"), meaning "100 Worries." The Modern Chess term "rook" derives from the Persian word "rukh," meaning chariot—not castle. The game spread westwards after the Islamic conquest of Persia. Shatranj was long lived, being played for almost one thousand years.

In Shatranj the position of the white Shah (King) being on the right or left side was not fixed, though the Shahs always faced each other.

> 7th C. AD to 16th C. AD

Oblong Chess is a Shatranj variant mentioned in several Arab manuscripts, particularly the al-‘Adlî, in the 9th C. AD. Oblong was also named al-Tawîla (Long) or al-Mamdûda (Lengthened), and was known to be played in the court of Tamerlane in the 14th C. AD.

The checkered board with its light and dark squares was a European invention introduced around 1100 AD. There are many other Oblong variants, such as this or this.

< 9th C. AD to approx. 14th C. AD

Shatranj spread across the Arab world, through northern Africa, and into Europe, where it is now recognized as Medieval Chess. As Europeans knew nothing of elephants, the Elephant became a Bishop. Soldiers became known as Pawns, the word Pawn being derived from the Old French word paon, meaning "soldier," and having the same derivation as peon.

Each file's Pawn was given the name of a commoner's occupation: 1) "Gambler", 2) "Guard", 3) "Innkeeper", 4) "Merchant", 5) "Doctor", 6) "Weaver", 7) "Blacksmith," and 8) "Farmer." The most famous example of this is found in the second book ever printed in the English language, The Game and Playe of the Chesse.

10th C. AD to 16th C. AD

Makruk is a close relative of Chaturanga, and is regarded as the most similar living game. Chaturanga likely arrived in Cambodia and Siam/Thailand by way of Java, and skipped the Persian version Shatranj altogether. Makruk is more popular in Thailand than Modern Chess. There are currently more than two million Thais who play Makruk.

In starting position, Pawns are placed on the third and sixth ranks, to speed up play. Counsellors are placed at the right side of Kings. A Pawn that reaches the sixth rank is always promoted to a Counsellor. The Bishop (known as a Nobleman) moves in the same way as the Chaturanga Elephant.

A perhaps more historical representation of Makruk is here.

< 12th C. AD to today

Courier Chess thrived in central Europe, especially Germany, from the 12th C. AD, and was played for at least six hundred years, being played alongside Medieval Chess. It pioneered the modern Bishop (then called the Courier), and played a key part in evolving Medieval Chess to Modern.

The Courier was considered so important that it stood among the tallest pieces, often depicted as a crescent moon. In addition, a Sage was added, which moves like the King, and a Jester, which moves one space along rank or file. Courier Chess is still considered one of the best chess variants.

At the start of Courier Chess each player must move his rook Pawns, his queen Pawn, and his Queen two squares forward. You may try Courier Chess without the opening moves here.

12th C. AD to 18th C. AD

The modern game of Chess started around 1475 in Spain when the Queen and Bishop got much more powerfull moves. Pawns gained the option of advancing two squares on their first move to speed up the game. Castling, derived from the "Kings Leap" to bring the king to safety, was introduced. Also, in the 19th C. AD, the convention that White moves first was established.

This form of chess got such names as "Queen's Chess" or "Mad Queen Chess."

15th C. AD to today

In 1881, Capt. George Hope Verney wrote a booklet for four player Chess he called "Four-Handed Chess." Verney's game received much attention in and outside London, and London hosted a four-handed chess club from 1885 till World War II.

Four-Handed Chess is often played in a team format.

1881 to 1940

Double Chess is a chess variant invented by Julian S. Grant Hayward which was published in the January 1929 issue of British Chess Magazine. The game is played on a 12×16 chessboard with each player in control of two complete armies placed side-by-side.

In Double Chess the Pawns have an initial up-to-four steps move.
Double Chess is curious when played in a team format.

1929

Tweedle Chess was created by the English chess enthusiast Vernon Rylands Parton (1897–1974). Many of Parton's variants were inspired by the works of Lewis Carroll.

In Tweedle Chess each player has two Kings and two Queens on a 10×10 board. A player wins by checkmating either one of the opposing Kings. While the pair of Queens will provide the player's main hopes for victory, the twin Kings "Tweedledum" and "Tweedledee" jointly provide ample headache.

1960

In 1969, Martin Gardner, the American popular mathematics and science writer, suggested a chess variant on 5×5 board. Gardner Minichess was largely played in Italy, and opening theory was developed. Statistics of finished games is: White won 40%, Black 28%, 32% draws.

In 1989, Gardner proposed another setup, which he called Baby Chess, where the black pieces are mirrored. Another popular varient, by Jeff Mallett, has white with two Knights against two black Bishops, see Mallett Minichess.

1969

Forchess was developed in 1975 by T. K. Rogers, who wanted to create a pure strategy game with the social dynamic of card games like Bridge. Rogers also wanted standard Chess pieces and board so that everything necessary to play would be easily available.

Pieces move and capture in the same manner as chess, except the pawn, which moves diagonally and captures laterally.

Forechess is often played in a team format.

1975