The Humber is now an
estuary. When the world sea level was lower during the
Ice Ages, the Humber had a long freshwater course across what was then the dry bed of the
Anglo-Saxon period, the Humber was a major boundary, separating
Northumbria from the southern kingdom, though at its height Northumbria did cover areas south of the Humber. The
Kingdom of Lindsey, which today is Northern Lincolnshire, was part of Northumbria before being lost to
Mercia. The name Northumbria came from
Anglo-Saxon Norðhymbre (plural) = "the people north of the Humber".
 The Humber currently forms the boundary between the
East Riding of Yorkshire, to the north and
North East Lincolnshire, to the south.
From 1974 to 1996, the areas now known as the East Riding of Yorkshire, North Lincolnshire and North East Lincolnshire constituted the county of
On 23 August 1921, the British
R38 crashed into the estuary near Hull, killing 44 of the 49 crew on board.
The estuary's only modern crossing is the
Humber Bridge, which was the longest single-span
suspension bridge in the world from its construction in 1981 until 1998. It is now the
Before the bridge was built, a series of
paddle steamers operated from the
Corporation Pier railway station
 at the
Victoria Pier in Hull to the
railway pier in New Holland. Steam ferries started in 1841, and in 1848 were purchased by the
Manchester, Sheffield and Lincolnshire Railway. They, and their successors, ran the ferry until the bridge opened in 1981.
 Railway passenger and car traffic continued to use the pier until the end of ferry operations.
The line of the bridge is similar to an ancient ferry route from Hessle to
Barton upon Humber, which is noted in the
Domesday Book and in a charter of 1281. The ferry was recorded as still operating in 1856, into the railway era.
 The Humber was then one mile (1.6 km) across.
Humber Forts were built in the mouth of the river for the
First World War. Planned in 1914, their construction started in 1915 and they were not completed until 1919.
 A coastal battery at Easington, Fort Goodwin or Kilnsea Battery, faced the Bull Sands Fort.
 They were also garrisoned during the Second World War, and were finally abandoned for military use in 1956.
Fort Paull is further upstream, a Napoleonic-era emplacement replaced in the early 20th century by Stallinborough Battery opposite
Graham Boanas, a Hull man, is believed to be the first man to succeed in wading across the Humber since
ancient Roman times. The feat, in August 2005, was attempted to raise cash and awareness for the medical research charity,
DebRA. He started his trek on the north bank at
Brough; four hours later, he emerged on the south bank at
Whitton. He is 6 feet 9 inches (2.06 m) tall and took advantage of a very low tide.
 He replicated this achievement on the television programme
Top Gear (Series 10 Episode 6) when he raced
James May who drove an
Alfa Romeo 159 around the inland part of the estuary without using the Humber Bridge.
Crossing by swimming
On Saturday 26 August 1911, Alice Maud Boyall became the first woman to swim the Humber. Boyall, then aged 19 and living in Hull, was the Yorkshire swimming champion. She crossed the Humber from Hull to New Holland Pier swimming the distance in 50 minutes, 6 minutes slower than the men's record.
Since 2011 Warners Health have organised the 'Warners Health Humber Charity Business Swim'. Twelve swimmers from companies across the Yorkshire region train and swim in an ellipse from the south bank to the north bank of the river under the Humber Bridge over a total distance of approximately 1 1⁄2 miles (2.4 km).