Complex sentence: The Vikings attacked early in Beorhtwulf's reign: the province of Lindsey was raided in 841, and London, a key centre of Mercian commerce, was attacked the following year.
Split into simpler sentences: The Vikings attacked early in Beorhtwulf's reign. The province of Lindsey was raided in 841, and London, a key centre of Mercian commerce, was attacked the following year.