 Complete the following phrase:  Almost immediately following Haruns departure, Nikephoros violated the peace terms by refortifying the sacked frontier forts and stopping tribute payments. However, Haruns preoccupation with a rebellion in Khurasan, and his death three years later, prevented a reprisal on a similar scale to 806. Smaller-scale raids continued on both sides, but the Abbasid civil war, which began after 809, and the Byzantine preoccupation with the Bulgars contributed to a cessation of large-scale 