Final answer:
Julius Caesar claims to be as constant as the northern star on the day of his assassination, which is a line from Shakespeare's play showing his self-perceived steadfast character.
Step-by-step explanation:
On the day of his assassination, Julius Caesar declares that he is as constant as the northern star, symbolizing his unwavering and steadfast nature. This famous line comes from William Shakespeare's play Julius Caesar, which, although historically inspired, is a work of drama, and the phrase specifically is part of a theatrical account rather than a verbatim historical record. In the context of the play, this declaration is meant to convey Caesar's self-image as an unchangeable and resolute leader, immune to the persuasions and whims that affect ordinary men.