1. A system of public libraries throughout the Islamic Empire was established by?

2. Who appointed judges to oversee legal disputes, leading to the development of Islamic jurisprudence?

3. System of weights and measures which led to standardization of trade throughout the Islamic Empire was established by?

4. "The best of you is the one who is best to his family"? is saying of?

5. Diplomacy, including the negotiation of peace treaties with neighboring states was adopted by?