# git merge-base > Find a common ancestor of two commits. > More information: . - Print the best common ancestor of two commits: `git merge-base {{commit_1}} {{commit_2}}` - Output all best common ancestors of two commits: `git merge-base --all {{commit_1}} {{commit_2}}` - Check if a commit is an ancestor of a specific commit: `git merge-base --is-ancestor {{ancestor_commit}} {{commit}}`