Leave only a specific directory in git history

Sometimes you want to limit the history of a git repository to only a specific sub-directory. git filter-branch to the rescue!

Try something like that:

git filter-branch --subdirectory-filter sub/directory -- --all

Note this might not end well, as indicated by the huge warning. Also, you might want to prune your reflog and do a git gc afterwards, especially if the original repository is huge.