git log

# Show all previous commit message and hash
git log

# Show the last n-commit message and hash
git log -n

git reflog

# Look at the history of the git operations performed at `HEAD`
git reflog

# view detailed action history of all branches (incl. stash)
git reflog -all

Start a New Git History

Squashing every change up until current changes.

Create a new orphan branch at the tip (i.e. the most recent commit) of your current branch

• This orphan branch forms the initial root commit of an entirely new and separate commit history tree, which is effectively equivalent to squashing all commits

git checkout --orphan new-master master
git commit -m "new initial commit"

# Overwrite the old master branch reference with the new one
git branch -M new-master master