Ancient Britain and the Invasions of Julius Caesar

by T. Rice Holmes

If we are to accept the premiss on which Airy himself lays so much stress, namely, that in 55 B.C. the tidal currents in the Channel, at any given period of the moon’s age, were the same as they are now, Caesar did not land at Pevensey. Airy, as we have seen, assumes that Caesar landed, in 55 B.C., on the third day before the full moon, and, appealing to the authority of Sir F. W. Beechey, he affirms that, off Hastings, the current turns westward five miles from the coast two hours later than it does close inshore. ‘If,’ he concludes, ‘we suppose Caesar to have first attempted the neighbourhood of St. Leonards, the tide, which a few miles from shore had turned to the west at 11 h., was, at 3 h., running in full stream to the west.’[3004] But, in order to prop up his theory, Airy is forced to place Caesar’s anchorage at five nautical or nearly six statute miles from the shore. To prove that such an assumption is absurd, it is only necessary to say that, at a distance of five nautical miles, Caesar could not have seen the armed men who, as he tells us,[3005] were swarming upon the cliffs, without the assistance of a powerful telescope.[3006] Lewin[3007] rightly concludes that Caesar must have anchored within a mile from the shore, at the outside, and probably within half a mile. Now high water at Dover on the 27th of August, 55 B.C., occurred at 7.42, and therefore at Hastings at 7.23 a.m.[3008] But off Hastings, within a mile from the shore, the current turns westward about the time of high tide,[3009] runs westward for about six hours and a half, and then runs eastward for about six hours. At 3 p.m., therefore, on the 27th of August, the tide off Hastings would have been running eastward, and would have continued to do so until about 7.50 p.m. And on the 28th of August, which Airy wrongly assumes to have been the day of Caesar’s landing, the tide off Hastings would have turned eastward about 2.53 p.m., and would have continued to run in that direction until about 8.53. Consequently, on the theory of the tides which Airy himself so strenuously maintains, it would have been impossible for Caesar to sail with the tide from Hastings or from St. Leonards to Pevensey.[3010] Even on Airy’s assumption that Caesar anchored five nautical miles from the shore, his theory cannot stand: he can only make a show of propping it up by assuming that Caesar landed on the 28th of August. On the 27th, the stream would have turned westward at about 9.30 a.m., and would have ceased running westward about 4 p.m. Therefore, even supposing that Caesar started on his seven miles’ sail in the ninth hour,[3011] he would have done so on the very last of the tidal stream, when it was barely moving; and it would have turned against him before he had half finished his voyage.

Very wisely, from his own point of view—for his silence has hitherto passed unnoticed—Airy ignored Caesar’s account of the voyage of his cavalry transports. Some of them, as we have seen, were ‘swept down in great peril’ (magno suo cum periculo deicerentur[3012]), evidently running before the gale, ‘to the lower and more westerly part of the island’ (ad inferiorem partem insulac quae est propius solis occasum[3013]): the others were carried back to the port from which they had started. That port, according to Airy, was the mouth of the Authie. The gale evidently blew from about the north-east; but, in order to give Airy the fullest latitude, I will assume that it was from the north-north-east, although in either case the ships which ran before the wind, once they had got under the lee of Beachy Head, would have been in smooth water! The course which the transports would have had to steer for the Authie, if they had been sighted off Pevensey, would have been SE. by E. 2° S., or within less than nine points of the wind. But in the gale they could hardly have made less than four points of lee-way.[3014] Therefore, in order to reach their supposed destination, they would have been obliged to lie within less than five points of the wind, which they could not have done.[3015] ‘No!’ said the harbour-master of Dover to me, after he had studied the chart, ‘No! they would have fetched Dieppe.’[3016] I have assumed that they could work to windward: if they could not, it is self-evident that they could not have returned to the mouth of the Authie.

But if any one is not convinced, let him hear Airy plead his own cause.

1. Airy argues that Volusenus would never have recommended Caesar to land under the cliffs of Dover, or at any point under the cliffs between Folkestone and Hythe. ‘No commander,’ he says, ‘would steer ships to a mural cliff three hundred feet high, with the intention of landing in order to invade the country; nor would any defenders station themselves there to repel an invasion; nor could a “telum” be thrown with any aim. But a daring officer might steer to a less perpendicular cliff, ten to thirty feet high, with the intention of forcing a landing.... Such are the cliffs between Hastings and Pevensey; and I conclude that they answer exactly to Caesar’s description.’ Assuming that the cliffs off which Caesar anchored, when he first approached the British coast, were in the neighbourhood of St. Leonards, Airy affirms that ‘the run of eight[3017] miles would bring him to the beach of Pevensey, answering perfectly to his description’.[3018]

Now whether Caesar did or did not steer towards ‘a mural cliff three hundred feet high’, he certainly anchored off cliffs which he calls ‘precipitous heights’ (angusti montes); and Airy makes too great a demand upon our credulity when he requires us to believe that Caesar described by the words angusti montes a ‘cliff ten to thirty feet high’. So much for the theory that Caesar anchored off the clifflets of St. Leonards:[3019] the argument that he could not have anchored off the cliffs of Dover shall be considered in its proper place. The reader has of course already observed that Volusenus, being a sane man, would never have recommended Caesar to ‘force a landing’ under any cliffs, great or small.

2. Airy argues that the Britons would naturally have assembled at Pevensey in order to oppose Caesar’s landing, because ‘Pevensey was the weakest point of Britain’.[3020] No! replies Lewin, Pevensey was not then the weakest point; for it was ‘backed by the Andred Forest’.[3021] Airy[3022] triumphantly observes that William the Conqueror landed there; but Lewin[3023] rejoins that when William landed the forest presented less difficulty to an invader than in Caesar’s time, as the Romans and the Saxons must have made clearances. Be this as it may, it is certain that William did not attempt to march northward through the forest. He returned, immediately after his victory, to Hastings: from Hastings he marched eastward to Romney, and from Romney to Dover.[3024] He had his own reasons for landing at Pevensey: but Caesar, for reasons equally good, chose the shortest passage; and although, as I have shown,[3025] these words are not to be taken in an absolutely literal sense, they alone exclude the notion that Caesar landed in Sussex. Obviously it is in the last degree improbable that Volusenus would have reconnoitred the coast so far westward as Pevensey; nor could the Britons have expected that Caesar would be so foolish as to double the length of his voyage in order to land there.[3026]

3. Airy argued that, except on the hypothesis that Caesar landed at Pevensey, it is impossible to account for the long duration of his first voyage. His rate of sailing, said Airy, if, as Dr. Guest maintained, he had started from Wissant and anchored off the Dover cliffs, would not have exceeded two miles an hour. ‘When in Shetland,’ he adds, ‘I have sailed in one of the ordinary fishing-boats of the country, hoisting a single lug-sail ... with a pleasant, easy breeze (sometimes dying away), from Lerwick to the head of Balta Sound, in Unst, in about eight hours. The distance, as measured on the Admiralty Chart, exceeds forty nautical miles.’[3027]

This was one of Airy’s more plausible arguments; and it demands consideration. To begin with, it must be pointed out that Caesar did not, as Dr. Guest believed, sail from Wissant, but from Boulogne, which is more than seven nautical miles further from Dover. Airy assumed[3028] that Caesar’s first voyage lasted from midnight till 10 a.m. But it is impossible to say how long it lasted. Caesar does not say that he started at midnight: he says that he started ‘about the third watch’ (tertia fere vigilia); and the third watch lasted, on the night of the 25th-26th of August, from midnight till 2.32 a.m., on the night of the 26th-27th till 2.33 a.m.[3029] Nor does he say that he reached Britain at 10 a.m.; he says that he reached it ‘about the fourth hour of the day’, which lasted on the 26th of August from 8.33 to 9.42.[3030] As Mr. Peskett says, ‘the possible duration of the voyage lies between the extreme limits of 9 h. 40′ and 6 hours.’[3031] Split the difference, and you will find that the average rate of sailing would have been about three knots and a half per hour. The answer to Airy’s argument is that Caesar’s narrative is quite consistent with the view that his ships may have remained for some time anchored off the Gallic coast in the expectation that the cavalry transports would sail out of Ambleteuse harbour to join them; and, further, that the wind may have shifted to an unfavourable quarter before the voyage was at an end.[3032]

4. Airy[3033] maintains that a river corresponding with Caesar’s description of the one on the banks of which he defeated the Britons on the day after his second landing,[3034] is to be found in the neighbourhood of Pevensey, and of Pevensey only. That river, he says, was the Rother, and the scene of the victory was Robertsbridge. He produces evidence to show that if Rye Sluice were broken, ‘the whole valley at Robertsbridge would now become a great tidal morass.’ This, he continues, ‘was its state in the age of Caesar, and it must have been a very formidable defence against an army advancing from the coast.’

Undoubtedly; so formidable that it would have been absolutely impassable. How Caesar’s cavalry succeeded in forcing their way over this ‘great tidal morass’ Airy omits to explain. If he had studied Caesar’s description[3035] of the much less formidable morass over which his ablest marshal, Labienus, tried in vain to construct a causeway, and from which he was obliged to retreat, he would hardly have made Caesar attempt to cross ‘a great tidal morass’ in the face of an enemy.