Persians had a great influence on their conquerors. The caliphs adopted many Sassanid administrative practices, such as coinage, the office of vizier, or minister, and the divan, a bureaucracy for collecting taxes and giving state stipends. Indeed, Persians themselves largely became the administrators. It is well established that the Abbasid caliphs modeled their administration on that of the Sassanids. The caliphs adopted Sassanid court dress and ceremony. In terms of architecture Islamic architecture borrowed heavily from Persian architecture. The Sassanid architecture had a distinctive influence over Islamic architecture.