Complex sentence: The Abbasid control of Samarkand soon dissipated and was replaced with that of the Iranian Samanids (AD 862-999), though it must be noted that the Samanids were still nominal vassals of the Caliph during their control of Samarkand.
Split into simpler sentences: The Abbasid control of Samarkand soon dissipated and was replaced with that of the Iranian Samanids (AD 862-999). Though it must be noted that the Samanids were still nominal vassals of the Caliph during their control of Samarkand.