L'Antre du Tryphon

These simple steps will let you move a directory contained within a git repository into another one while preserving the history.

1. Make the parent directory of the source git repository current.
2. Execute the following command to export the directory you want to move
   git log --pretty=email --patch-with-stat --reverse --full-index --binary -- directory-to-export > /tmp/exportfile
3. Before importing the exported directory, you can tweak the destination directory. For example, you can import the directory content right into the current directory by removing directory-to-export/ in /tmp/exportfile
4. Clone the project you want to import into.
5. Make this project directory current
6. Import the exported directory in step 2 using the following command
   git am < /tmp/exportfile
7. Push the project directory.