Strange, I have always thought, as I walk to work of a morning, that a sign on the path alongside the Thames at Osney, reads “No Horses”. Supposing I wanted to tow a barge? After all, is that not what a towpath is for? But thereby hangs a tale . . .

For centuries arguments raged as to the ownership of and access to the riverbank, with landowners often insisting on charging tolls for horses and pedestrians alike. Even today, I gather from a new book by Joan Tucker, Ferries of the Upper Thames (Amberley £19.99) — which is packed with an astonishing amount of research — the river remains for a large part the property of private landowners.

They possess not only the riverbank on their land but also the river bed up to halfway across it — though the water itself is now the responsibility of the Environment Agency.

The public has no automatic right of access and in many parts of Oxfordshire you can only get to the Thames — except with the permission of a landowner — by following a lane that once upon a time led to a ferry; and many of these have now also been subsumed into desirable, and private, riverside properties.

Before the Reformation, even before the Norman conquest, when much of the Thames was controlled by monasteries and priories that owned the many water mills, it seems that boats were towed along not by horses but instead by gangs of men called ‘bow hauliers’ or ‘haylers’, who hung about and hired themselves out on an ad hoc basis.

Amazingly, such gangs continued to exist, and to compete with horses for work, well into the 18th century. A clergyman, John Fletcher, wrote: “How are they bathed in sweat and rain. Fastened to their lines as horses to their traces, wherein do they differ from the laborious brutes? Not in an erect posture of the body, for in the intenseness of their toil, they bend forward, their head is foremost, and their hand upon the ground.”

He adds: “The beasts tug in patient silence and mutual harmony; but the men with loud contention and horrible imprecations.”

Only gradually did the horses win the battle for work as, with the coming of the industrial revolution, barges became larger. Official towpaths became necessary and were negotiated with landlords by various commissions set up to make the Upper Thames more navigable. But often this meant that the horses had to cross the river by ferry because one landlord refused to let horses over land on his side of the river.

In the mid-19th century there was one ferry for every mile on the Thames between Kew and Lechlade. Now there are none.

By 1955, only five were left: Bablockhythe, made famous in Matthew Arnold’s The Scholar Gypsy; Temple, near Henley; Cookham, where two ferries operated; and one at Benson.

The general pattern for the development of crossing points on the Thames was, first, a ford (sometimes with a man there to give customers a piggy-back); then a ferry; and finally, if traffic justified it, a bridge.

Radcot and Newbridge vie for the honour of oldest bridge across the Thames, but Lechlade and Wallingford are not far behind. Typically, a crossing place was controlled in medieval times by a monastery which had a hostel nearby for travelers. Many pubs near bridges these days are the successors of such hostelries.

Wallingford was from earliest times an important crossing point, and William the Conqueror built a castle there to guard it. The first stone bridge was constructed in the early 12th century.

Between the wars it was realised that the towpath was no longer needed for navigation and was falling into serious, even dangerous, decrepitude. The idea of creating a long-distance path for hikers was then mooted, but did not finally become a reality until 1989 when the Thames Path was declared a National Trail. It took all those decades to work out alternative bridges and routes to replace the numerous old ferries.

So that is why horses are not allowed. The towpath is not a towpath. It is a footpath. Silly me.