As the Byzantine Empire declined under Basil's successors, invasions of Pechenegs and rising taxes contributed to increasing discontent, which resulted in several major uprisings in 1040–41, the 1070s, and the 1080s. The initial centre of the resistance was the theme of Bulgaria, in what is now Macedonia, where the massive Uprising of Peter Delyan (1040–41) and the Uprising of Georgi Voiteh (1072) took place. Both were quelled with great difficulty by Byzantine authorities. These were followed by rebellions in Paristrion and Thrace. During the Comnenian Restoration and the temporary stabilisation of the Byzantine Empire in the first half of the 12th century, the Bulgarians were pacified and no major rebellions took place until later in the century.