How to know the version of GRUB

For me the above answer given by @Daniel does not work. I have Ubuntu 14.04 LTS (this also works with Ubuntu 17.10) and to check the version of Grub (Grub2) I need to type:

grub-install --version

On clean ubuntu installs the grub package itself doesn't seem to be installed. Thus typing 'grub -anyoption' results in an error that says grub is not installed. However you can type for example

grub-install -v

And it will give you the correct version of grub currently installed

The version of the Grub is 1.99-21ubuntu3

EDIT: As others have pointed out the commandline flags have been changed in newer versions. So now instead of typing grub-install -v you'd have to use a capital 'V' or the explicit --version

This will roughly do the job:

dpkg -l | grep grub | grep ii

You should note that just to confuse things that the version 1.9x is known as Grub2. I think they number it in a similar way that people would call the 1600-1699, the 17th century.