At the time when The Song of Roland was written, the chivalric, or knightly, code was still considered of great importance in society. Knights were expected to adhere to a superior set of values that marked them off from mere mortals. As well as courage in battle, they were expected to act honorably and show themselves to be willing to sacrifice their lives for others.
All of these values are much in evidence in The Song of Roland and are displayed throughout by the title character. Despite being something of a hothead with a rash, impulsive nature, Roland is still able to understand the importance of acting in the correct manner and of sticking to the chivalric code, come what may.
The most significant illustration of this comes during the Battle of Roncevaux Pass. Even though the situation is desperate, instead of using his trusty horn to summon help, Roland continues to fight on bravely, just as a valiant knight would be expected to do.
Roland has made the supreme sacrifice, and in doing so he has illustrated once again the importance of the chivalric code in getting people to see beyond their own narrow interests and realize that we are all part of something much bigger than ourselves.