Explain the concept of vassalage, the responsibilities you would have as a vassal to Martel, and what obligations are expected from you as his vassal.

You are a warrior who has fought with Charles Martel at Tours against the Umayyads. Your deeds on the battlefield have distinguished you in Martel’s eyes resulting in his offer of land in his realm and knighthood if you agree to be his vassal. Explain the concept of vassalage, the responsibilities you would have as a vassal to Martel, and what obligations are expected from you as his vassal. What would be his and your legal obligations?