The Arab raids from 712 on penetrate ever deeper into Anatolia, with the final objective of mounting an assault on Constantinople.

Emperor Anastasios constructs extensive military fortifications in and around Constantinople, which the Arabs, renewing their assaults by land and sea, again besiege in 717, lured by the unsettled conditions following the second deposition of Justinian II.

The repulsion in 718 of the second Arab siege of Constantinople is a major imperial success, and halts Arab attacks against the Empire for a few years.