The main contributions of the Umayyad Dynasty are:
1. The capital of Islam was moved to Damascus, Syria
2. Expansion of Islam touched the regions of India, China, North Africa, and Spain
3. Arabic became the official language.
4. Arabian currency was used in the Empire
5. Roads were built
6. Postal routes were created.
The main contributions of the Abbasids Dynasty are:
1. The Abbasids established their capital at Baghdad, near the ruins of the ancient Iranian metropolis, Ctesiphon.
2. The army and bureaucracy were reorganised on a non- tribal basis to ensure greater participation by Iraq and Khurasan.
3. The Abbasid rulers strengthened the religious status and functions of the caliphate and patronised Islamic institutions and scholars.
4. They maintained the magnificent imperial architecture and elaborate court ceremonials of the Umayyads.
