From the Talhoffer Fechtbuch (or Master Hans Talhoffer’s Fight book) of the 15th Century

Thereupon speaks Hans Talhoffer:

The good man must speak up for the truth – even when falsehood is commonplace.

There are seven causes wherefore a man has a duty to fight:

The first is Murder
The second is treason
The third is heresy
The fourth is becoming an encourager of disloyalty to one’s lord.
The fifth is betrayal in strife or otherwise (Desertion/ traitor)
The sixth is falsehood
The Seventh is using either a maiden or a lady (sexual abuse)

Here the winner thanks God; as he had great need; and there lies the loser dead…
Whom they carry away to the freedom of the grave that God has for all worthy souls. Amen.