The emerging tribes of LPRIA in southern and eastern Britain had a long history of contact with the Roman world and were heavily influenced by Roman attitudes and actions because Rome saw all her neighbours as within her sphere of influence. Whether or not the British tribes still paid tribute, some of them had been subject to Roman control following the invasion of Julius Caesar in 55 and 54 BC (DBG V.22). This precedent meant, for the Roman emperors, that the island lay within their legitimate sphere of interest. This interest had already been shown by both Caligula (Suetonius, Caligula 44, 46) and Augustus (Dio 49.28, 2; 53.22, 5; 53.25, 2), who had contemplated and prepared for invasion. Such direct intervention following a long period of indirect contact had precedents, for the general pattern of Rome’s expansion saw her first taking an indirect interest, then a successively more active role before assuming absolute control. In the case of Britain this process was slow, since annexation had been delayed first by the civil wars, next by Augustus’ interests in Germany and elsewhere, then by Tiberius’ static frontier policy and finally by the troubles of Caligula. Notwithstanding this, the question should not be why Claudius invaded Britain, but why it had not happened earlier.