The Roman city of Verulamium, the second-largest town in Roman Britain after Londinium, developed from the Celtic settlement and was granted the rank of "municipium" around AD 50, meaning that its citizens had what were known as "Latin Rights", a lesser citizenship status than a "colonia" possessed. It grew to a significant town, and as such received the attentions of Boudica of the Iceni in 61, when Verulamium was sacked and burnt on her orders:excavations preceding the museum's new entrance done in 1996–97 within the centre of the Roman town gave archaeologists the chance to date a black ash layer to 60–65 AD, thus confirming the Roman written record. It grew steadily; by the early 3rd century, it covered an area of about , behind a deep ditch and wall. Verulamium contained a forum, basilica and a theatre, much of which were damaged during two fires, one in 155 and the other in around 250. These were repaired and continued in use in the 4th century. The theatre was disused by the end of the 4th century. One of the few extant Roman inscriptions in Britain is found on the remnants of the forum (see Verulamium Forum inscription). The town was rebuilt in stone rather than timber at least twice over the next 150 years. Roman occupation ended between 400 and 450 AD