Complex sentence: Under Seljuq rule many pre-Islamic Iranian traditional arts including the Sasanian traditional architecture resurrected, and indulged many of the great Iranian scholars;-at the same time the Islamic religious institutions became more organized and Sunni orthodoxy became more codified.
Split into simpler sentences: Under Seljuq rule, many pre-Islamic Iranian traditional arts including the Sasanian traditional architecture resurrected, and indulged many of the great Iranian scholars. At the same time, the Islamic religious institutions became more organized and Sunni orthodoxy became more codified.