The Challenge

A knight would stand ready in front of a bridge or a ford.
And challenge those to fight to the death if they carried a sword.
A fight to the death might break out if it must.
Until a lethal battle left one defeated in the dust.
If the knight was dead, the swordsman it is generally said.
Could claim a name of higher fame for the fight with the knight.
But there is a point if someone who knew.
Could plead his case with the knight and be let through.
This knightly lore was only known by very few.