Complex sentence: The settlement continued to exist until the collapse of the Western Roman Empire, after which all traces of it were lost and it was not until the pioneering work of Pierluigi Galletti in the mid- 18th century that Capena's former location was decisively identified.
Split into simpler sentences: The settlement continued to exist until the collapse of the Western Roman Empire, after which all traces of it were lost. It was not until the pioneering work of Pierluigi Galletti in the mid- 18th century that Capena's former location was decisively identified.