What responsibility is given to the caliph in the first duty?

The responsibility that is given to the Caliph in the first duty is to protect the faith of Islam as per the principles laid down by consensus of the early Muslims (salaf al-ummah). Apart from this responsibility, there are 9 other responsibilities as well. Some of the other responsibilities include executing the offenders for preserving justice. Also the Caliph has the responsibility of protecting the lives of people that are governed by him, so that they can pursue their livelihood and lead a peaceful life.