Pressure is rising on the French government to return items that activists say were stolen during “the pillage of Africa”.
Mr Diyabanza, 41, defended what he called a "political act" and said it was about time that Africans, Latin Americans and other colonised communities took back stolen treasures.
He accuses European museums of making millions on artworks taken from now-impoverished countries such as Congo. The pole, which came from current-day Chad, should be among works returned to Africa, he said.
The five activists could face up to 10 years in prison if found guilty of attempted theft of a registered artwork.
But prosecutors have asked for a fine of €1,000 (£907) for Mr Diyabanza and €500 each for his alleged accomplices.
After removing the artefact, he allegedly paraded it around the museum, claiming: “We’re taking it home.”
Museum guards stopped the group and police detained them. After his arrest, Mr Diyabanza, sued the French state, accusing it of "theft and receiving state goods", the BBC reported.
He has staged three livestreamed museum protests in recent months — in Paris, Marseille and the Netherlands.
"We are the legitimate heirs of these works," he told the court. But he insisted that "appropriation wasn't my goal... The aim was to mark the symbolism of the liberation of these works."
He has previously criticised the French government's speed in returning artefacts to African nations.
A 2018 study commissioned by President Emmanuel Macron recommended that French museums give back works that were taken without consent, if African countries request them.
So far, France is preparing to give back 26 works of African art out of 90,000 works believed to be in French museums, most in the Quai Branly.
Emmanuel Kasarherou, director of the Quai Branly Museum said: “The issue of restitution… deserves a serious debate.”
A verdict in the trial is expected next month.