It rises in the High Weald, West Sussex and flows through Tonbridge, Maidstone and the Medway conurbation in Kent, before emptying into the Thames Estuary near Sheerness, a total distance of 70 miles (113 km).

[3] The river and its tributaries flow through largely rural areas, Tonbridge, Maidstone and Medway being the exceptions.

In 1746, improvements to the channel meant that barges of 40 long tons (41 t) could reach East Farleigh, Yalding and even Tonbridge.

Downstream of the Medway bridges (M2, HS1) the river comprises a sequence of tidal reaches:[5] One of the channels on the southern side of the estuary, Stangate Creek,[6] is the subject of a painting by William Turner.

[7] In a location described as "opposite the Isle of Grain, Sharpfleet Creek, and the lower-end of the Hope", a quarantine site for ships was proclaimed on 16 September 1709, during an outbreak of the plague.

Tonbridge has suffered frequent flooding over the centuries, so much so that the higher part of the town to the north is called "Dryhill".

In recent years the village of Yalding, about 12 km downstream at the confluence with the River Beult, has been more prone to flooding than Tonbridge.

At West Peckham, it is joined by the Wealdway which continues through Tonbridge, thus linking with the Eden Valley Walk.

The Romans left evidence of many villas in the lower Medway Valley; later Jutish burial sites have also been found.

Castles became a feature of the landscape, including Rochester, Allington, Leeds (near Maidstone), and West Malling.

The hop fields in the vicinity of the latter are also described; and the easterly River Len, which then supplied Maidstone with its piped water.

The book states that Within about two miles of Tunbridge the Medway branches out into several small streams, five of which unite at the town ... having each its stone bridge.

The Thames and Medway Canal, duplicatively linking the estuary at Strood to Gravesend for adverse tides and weather was completed in 1824 but was not a commercial success; by 1849 the South Eastern Railway had taken over its tunnel through a hillside.

The Hartlake disaster of 1853 saw the deaths of 30 hop-pickers when a wagon carrying them crashed through the side of a rotten wooden bridge at Golden Green near Hadlow, throwing its passengers into the flood-swollen river.

[15] In 1914 HMS Bulwark exploded while moored at Kethole Reach near Sheerness, killing 741 men with only 12 survivors.

In 1942 the world's first test of a submarine oil pipeline was conducted with one laid across the Medway in Operation Pluto.

[16] The Medway's 'marriage' to the Thames is given extensive treatment by Edmund Spenser's The Faerie Queene in the 16th century (Book IV, Canto xi).

[citation needed] The River Medway is featured at Maidstone in the studio backdrop of the ITV1 regional news programme Meridian Tonight.