The area that today is Chad was once inhabited by a group of politically disconnected tribes. Humanoid skulls and cave paintings of great antiquity have been found there. Gradually relatively weak local kingdoms developed; these were later overtaken by the larger and more powerful Kanem-Bornu Empire.Later, foreigners came to have more influence in Chad. Beginning in the Middle Ages, Chad became a crossroads for Muslim traders and indigenous tribes. In 1900, after the battle of Kousséri, Chad became a part of France's colonial system.
In WWII, Chad was the first French colony to join the Free French and the Allies, under the leadership of its Governor, Félix Éboué. In 1960, Chad became an independent country, with François Tombalbaye as its first president.
Chad's post-independence history has been marked by instability and violence stemming mostly from tensions between the mainly Arab-Muslim north and the predominantly animist and Christian south.
In 1998 an armed insurgency began in the north, led by President Déby's former defence chief, Youssouf Togoimi. A Libyan-brokered peace deal in 2002 failed to put an end to the fighting.
In 2003 and 2004, unrest in neighbouring Sudan's Darfur region spilled across the border, along with many thousands of refugees.
On December 23, 2005, Chad announced that it was in a "state of war" with Sudan. The Organisation of the Islamic Conference (OIC) has urged Sudan and Chad to exercise self-restraint to defuse growing tension between the two neighboring countries.
On February 8, 2006, Chad and Sudan signed the Tripoli Agreement, ending the Chadian-Sudanese conflict. This agreement prohibits either country from beginning media campaigns against one another, and also from interfering with the others internal affairs.
On April 13, 2006 rebels invaded the Capital, seeking to topple the Presidency of Idriss Déby. Government forces defeated them in the Battle of N'Djamena. Chad then accused Sudan of supporting and training the rebels, and severed diplomatic ties between the two countries.