During the six years after Rick's assumed death, Michonne selected some members of Alexandria to help her govern the community and make important decisions for all the residents, such as determining if survivors should be granted permission to joining the settlement. While most of the council is made up of Alexandrians, one is a former high-ranking Savior who joined the community following the fall of the Sanctuary. While the council is officially lead by Gabriel Stokes, Michonne has full veto power when it comes to matters involving security. However, in one instance, the council went around Michonne by not telling her about Eugene's plan to install a radio repeater as they knew she'd veto it.
The council is shown making decisions such as whether or not to allow Magna's group to stay, how to handle the Whisperers' increasing threat and how to deal with Negan accidentally killing Margo while protecting Lydia. In that case, they were seen taking testimony from Gage and Alfred and Daryl Dixon suggested that Negan would get to tell his side of the story, with the council effectively acting as a tribunal weighing the case. As Michonne was not present, she was able to appoint Daryl as her proxy to vote on Negan's fate, though she left the decision of what to vote on up to him, something the council accepted without issue. When the vote was tied leaving Gabriel as the decider, he was able to delay the decision by taking the night to think over what he would do rather than voting right then.
When the Coalition was formed, Michonne had Gabriel sign the charter as the head of the council. In the same meeting, Gabriel stated that he had the council take an informal vote at the Kingdom's trade fair to grant Lydia asylum in Alexandria following her defection from the Whisperers.