Under successive governors the size of the province of Britain continued to grow, till in the reign of Nero it had advanced up to the line of the Severn and Humber, and included all the central and southern counties of modern England. But the wild tribes of the Welsh mountains and the Yorkshire moors opposed a determined resistance to the conquerors, and did not yield till a much later date. While the governor Suetonius Paulinus was engaged in a campaign on the Menai Straits, against the tribe of the Ordovices, there burst out behind him the celebrated rebellion of Queen Boudicca (Boadicea). This rising began among the Iceni, the tribe who dwelt in what is now Norfolk and Suffolk. They had long been governed by a vassal king; but when he died sonless, the Romans annexed his dominions and cruelly ill-treated his widow Boudicca and her daughters. Bleeding from the Roman rods, the indignant queen called her tribesmen to arms, and massacred all the Romans within her reach. All the tribes of eastern Britain rose to aid her, and the rebels cut to pieces the Ninth Legion, and sacked the three towns of Londinium, Verulamium, and Camulodunum,[1] slaying, it is said, as many as 70,000 persons in their wild cruelty. But presently the governor Paulinus returned from his campaign in Wales at the head of his army, and in a great battle defeated and destroyed the British hordes. Boudicca, who had led them to the field in person, slew herself when she saw the battle lost (A.D. 61). [Sidenote: =Agricola Governor of Britain, A.D. 78-85.=] Southern Britain never rose again, but the Romans had great trouble in conquering the Silurians and Ordovices of Wales, and the Brigantes beyond the Humber. They were finally subdued by the great general Agricola, who governed the British province from 78 to 85. This good man was the father-in-law of the historian Tacitus, who wrote his life--a document from which great part of our knowledge of Roman Britain is derived. After conquering North-Wales and Yorkshire, Agricola marched northward against the Gaelic tribes of Scotland. He overran the Lowlands, and then pushed forward into the hills of the Highlands. At a spot called the Graupian Mountain (_Mons Graupius_) somewhere in Perthshire, he defeated the Caledonians, the fierce race who dwelt beyond the Forth and Clyde, with great slaughter. It was his purpose to conquer the whole island to its northernmost cape, and even to subdue the neighbouring Gaels of Ireland. But ere his task was complete the cruel and suspicious emperor Domitian called him home, because he envied and feared his military talents.