<Tr> <Th_colspan="2"> Strength </Th> </Tr> <Tr> <Td> 55 B.C--Around 10,000 legionary troops (Legio VII, Legio X), 80 infantry transport ships and an unknown number of cavalry forces . 54 B.C--Around 25,000 legionary troops (Legio VII and 4 other legions), unknown numbers of cavalry forces and transports . </Td> <Td> Unknown numbers of cavalry, infantry and chariots (4000 chariots attested in 55 BC) </Td> </Tr> <P> In the course of his Gallic Wars, Julius Caesar invaded Britain twice: in 55 and 54 BC . The first invasion, in late summer, was unsuccessful, gaining the Romans little else besides a beachhead on the coast of Kent . The second invasion achieved more: the Romans installed a king, Mandubracius, who was friendly to Rome, and they forced the submission of Mandubracius's rival, Cassivellaunus . No territory was conquered and held for Rome; instead, all Roman - occupied territory was restored to the allied Trinovantes, along with the promised tribute of the other tribes in what is now eastern England . </P> <P> Britain had long been known to the classical world as a source of tin . The coastline had been explored by the Greek geographer Pytheas in the 4th century BC, and may have been explored even earlier, in the 5th, by the Carthaginian sailor Himilco . But to many Romans, the island, lying as it did beyond the Ocean at what was to them the edge of the "known world," was a land of great mystery . Some Roman writers even insisted that it did not exist, and dismissed reports of Pytheas's voyage as a hoax . </P>

Who was leader of the romans when they invaded britain in 55 and 54 bc