The Historic Thames

by Hilaire Belloc

Below Oxford, after the entry of the Cherwell, and from thence down to a point not very easily determined, but which is perhaps best fixed at Wallingford, the Thames is only passable at fixed crossings in ordinary weather, as at Sandford, where the hard gravels approach the bank upon either side, and at other places, each distant from the next by long stretches of river.

It is not easy, now that the river has been locked, to determine precisely where all these original crossings are to be found.

The records of Abingdon and its bridge make it certain that a difficult ford existed here; the name "Burford" attached to the bridge points to the ancient ford at this spot. It is a name to be discovered in several other parts of England where there has been some ancient crossing of a river, as, for instance, the crossing of the Mole in Surrey by the Roman military road.

The next place below Abingdon may have been at Appleford, but was more likely between the high cliff at Clifton-Hampden and the high and dry spit of Long Wittenham. Below this again for miles there was no easy crossing of the river.

The Thames was certainly impassable at Dorchester. The whole importance of Dorchester indeed in history lies in its being a strong fortified position, and it depends for its defence upon the depth of the river, which swirls round the peninsula occupied by the camp.

It has been conjectured that there was a Roman ford or ferry at the east end of Little Wittenham Wood, where it touches the river. The conjecture is ill supported. No track leads to this spot from the south, and close by is an undoubted ford where now stands Shillingford Bridge.

Below this again there was no crossing until one got to Wallingford; and here we reach a point of the greatest importance in the history of the Thames and of England.

Wallingford was not the lowest point at which the Thames could ever be crossed. So far was this from being the case that the tidal Thames could be crossed in several places on the ebb, notably at the passage between Ealing and Kew, where Kew Bridge now stands; and, as we shall see, the Thames was passable at many other places. But the special character of the passage at Wallingford lay in the fact that it was a ford upon which one could always depend. Below Wallingford the crossings were either only to be effected in very dry seasons or, though normally usable, might be interrupted by rain.

It is at Wallingford, therefore, that the main lowest passage of the Thames was effected, and it was through Wallingford that Berkshire communicated with the Chilterns. Wallingford is, then, the second point of division upon the Thames when one is regarding that river as a defence or a boundary. Below Wallingford there was perhaps a regular crossing at Pangbourne; there was certainly a ford of great importance between Streatley and Goring; and all the way down the river at intervals were difficult but practicable passages—notably at Cowey Stakes between the Surrey and the Middlesex shore, a place which is the traditional crossing of Cæsar. The water here in normal weather was, however, as much as five feet deep, and this ford well illustrates the difficulties of all the lower crossings of the Thames.

The effect of the river as a barrier must, of course, have largely depended upon the level to which the waters rose in early times. It is exceedingly difficult to get any evidence upon this—first, because however far you go back in English history some sort of control seems always to have been imposed upon the river; and secondly, because the early overflows have left little permanent effect.