In 382, Magnus Maximus organized all of the British-based troops and attempted to establish himself as emperor over the west. The event was obviously important to the Britons, as "Macsen Wledig" would remain a major figure in Welsh folklore and several medieval Welsh dynasties claimed descent from him. He was probably responsible for London's new church in the 370s or 380s. He was initially successful but was defeated by Theodosius I at the 388 Battle of the Save. A new stretch of the river wall near Tower Hill seems to have been built further from the shore at some point over the next decade.