March 30 in History 598 – Balkan Campaign: The Avars lift the siege at the Byzantine stronghold of Tomis. Their leader Bayan I retreats north of the Danube River after the Avaro-Slavic hordes are decimated by the plague. 1282 – The people of Sicily rebel against the Angevin king Charles I, in what becomes known as the Sicilian Vespers. 1296 – Edward I sacks Berwick-upon-Tweed, during armed…