Thousands of people honored the veteran leader after he was killed in clashes with rebels. His death has pushed Chad into political unrest and alarmed Western powers over losing a key ally.
Chad's late President Idris Deby Itno will be buried on Friday after his funeral amid uncertainty over the country's democratic future.
The central African nation was thrown into turmoil after the military announced Deby's death on Tuesday, just one day after his reelection for a 6th term in office.
A close ally to Western powers, Deby was in charge of Chad's central role in counterterrorism operations in the Sahel and the Lake Chad Basin, where various Islamist extremist groups operate.
What are the funeral arrangements?
Thousands of people gathered at the main square in Chad's capital N'Djamena to honor the late president.
Mourners are set to commemorate his death with prayers at the Grand Mosque in N'Djamena.
Deby will be laid to rest alongside his father near his birthplace Berdoba, in the far east of the desert country near the border with Sudan.
Several African and European leaders are attending the funeral, including President Emmanuel Macron of France, the former colonial power in Chad.
Who is in charge in Chad now?
A military council led by Deby's son, General Mahamat Idriss Deby Itno has taken power. France has backed the transitional military government, AFP news agency cited the French presidency as saying.
Opposition leaders and the rebels accused of killing Deby have deemed the takeover a coup, but Mahamat Deby said Chad would hold democratic elections in 18 months.
The military council has warned that the fight over power in Chad was not yet over.
The Front for Change and Concord in Chad (FACT) rebel group, which is believed to have killed the late president, has reportedly threatened to depose his son.
How did Deby die?
Deby's reelection came amid boycott calls and criticism for cracking down on the opposition and shutting down the internet.
FACT, based in the country's north, had called for Deby to resign and attacked a border post on Monday, advancing towards N'Djamena.
Deby's campaign said he was headed to the northern part of the country to join troops in fighting terrorists. The military later said he was fatally wounded during his visit to the front lines of the battle against FACT.