A Wellington boot, often shortened to welly, and also known as a gumboot, rubber boot, or rain boot, is a type of waterproof boot made of rubber.

Originally a type of leather boot adapted from Hessian boots, a style of military riding boot, Wellington boots were worn and popularised by Arthur Wellesley, 1st Duke of Wellington. They became a staple of practical foot wear for the British aristocracy and middle class in the early 19th century. The name was subsequently given to waterproof rubber boots and they are no longer associated with a particular class. They are now commonly used for a range of agricultural and outdoors pursuits.

The term Wellington boot comes from Arthur Wellesley, 1st Duke of Wellington, who instructed his shoemaker to create the boot by modifying the design of the Hessian boot. The terms gumboot and rubber boot are both derived from the rubber modern Wellington boots are made from, with the term "gum" coming from gum rubber.

The terms Wellington boot and gumboot are most commonly used in British English, with the term being occasionally used in American English. Instead, the terms rubber boot and rain boot are more commonly used in American English. Further, in American English, the term Wellington boot is sometimes used to specifically refer to Wellington boots with a more fashionable design.

The Duke of Wellington instructed his shoemaker, Hoby of St. James's Street, London, to modify the 18th-century Hessian boot. The resulting new boot was fabricated in soft calfskin leather, had the trim removed and was cut to fit more closely around the leg. The heels were low cut, stacked around an inch (2.5 centimetres), and the boot stopped at mid-calf. It was suitably hard-wearing for riding, yet smart enough for informal evening wear. The boot was dubbed the Wellington and the name has stuck in English ever since. In the 1815 portrait by James Lonsdale, the Duke can be seen wearing the more formal Hessian style boots, which are tasselled.

Wellington's utilitarian new boots quickly caught on with patriotic British gentlemen eager to emulate their war hero. Considered fashionable and foppish in the best circles and worn by dandies, such as Beau Brummell, they remained the main fashion for men through the 1840s. In the 1850s they were more commonly made in the calf-high version, and in the 1860s they were both superseded by the ankle boot, except for riding. Wellington is one of the two British Prime Ministers to have given his name to an item of clothing, the other being Sir Anthony Eden (see Anthony Eden hat) whilst Sir Winston Churchill gave his name to a cigar, and William Gladstone (four times prime minister between 1868 and 1894) gave his to the Gladstone Bag, the classic doctor's portmanteau.

Production of the Wellington boot was dramatically boosted with the advent of World War I and a requirement for footwear suitable for the conditions in Europe's flooded and muddy trenches. The North British Rubber Company (now Hunter Boot Ltd) was asked by the War Office to construct a boot suitable for such conditions. The mills ran day and night to produce immense quantities of these trench boots. In total, 1,185,036 pairs were made to meet the British Army's demands.

In World War II, Hunter Boot was again requested to supply vast quantities of Wellington and thigh boots. 80% of production was of war materials, from (rubber) ground sheets to life belts and gas masks. In the Netherlands, the British forces were working in flooded conditions which demanded Wellingtons and thigh boots in vast supplies.

By the end of the war in 1945, the Wellington had become popular among men, women and children for wet weather wear. The boot had developed to become far roomier with a thick sole and rounded toe. Also, with the rationing of that time, labourers began to use them for daily work.

The lower cost and ease of rubber "Wellington" boot manufacture, and being entirely waterproof, lent itself immediately to being the preferred protective material to leather in all forms of industry. Increased attention to occupational health and safety requirements led to the steel toe or steel-capped Wellington: a protective (commonly internal) toe-capping to protect the foot from crush and puncture injuries. Although traditionally made of steel, the reinforcement may be a composite or a plastic material such as thermoplastic polyurethane (TPU). Such steel-toe Wellingtons are nearly indispensable in an enormous range of industry and are often mandatory wear to meet local occupational health and safety legislation or insurance requirements.

In July 1956, the Monopolies and Restrictive Practices Commission published its Report on the Supply of Certain Rubber Footwear, which covered rubber boots of all kinds including Wellingtons and overboots. This 107-page official publication addressed contemporary concerns about unfair pricing of rubber footwear manufactured in the UK or imported from overseas. The appendices include lists of rubber footwear manufacturers and price-lists of each company's range of Wellington boots available in the mid-1950s.

Green Wellington boots, introduced by Hunter Boot Ltd in 1955, gradually became a shorthand for "country life" in the UK. In 1980, sales of their boots skyrocketed after Lady Diana Spencer (future Princess Diana) was pictured wearing a pair on the Balmoral estate during her courtship with Prince Charles.

Wellington boots were at first made of leather. However, in 1852 Hiram Hutchinson met Charles Goodyear, who had just invented the sulfur vulcanisation process for natural rubber. Hutchinson bought the patent to manufacture footwear and moved to France to establish À l'Aigle ("At the Eagle") in 1853, to honour his home country. Today the company is simply called Aigle. In a country where 95% of the population were working on fields with wooden clogs as they had been for generations, the introduction of the wholly waterproof, Wellington-type rubber boot became an instant success: farmers would be able to come back home with clean, dry feet.

Wellington boots in contemporary usage are waterproof and are most often made from rubber or polyvinyl chloride (PVC), a halogenated polymer. They are usually worn when walking on wet or muddy ground, or to protect the wearer from heavy showers and puddles. They are generally just below knee-high although shorter boots are available.

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Before its entry into the mobile phone business, rubber boots were among the best-known products of Nokia.

Both the Finnish Defence Forces and the Swedish Armed Forces issue rubber boots to all soldiers for use in wet conditions and during the winter with felt liners.

Gebhard Leberecht von Blücher was Wellington's colleague at the Battle of Waterloo and there is speculation that some early emigrants to Australia, remembering the battle, may have confused a different design the Blucher shoe developed by Blucher. The Australian poet Henry Lawson wrote a poem to a pair of Blucher Boots in 1890.

• British country clothing
• Galoshes
• Mackintosh
• Paddington Bear
• Vermin Supreme
• Waders (footwear)
• William's Wish Wellingtons
• Welly wanging

• Nicholson, Jon, Rubber Boots: Understanding an Industry (PDF), NorthStar Rubber Specialties, L.L.C.
• Nicholson, Jon, Rubber Hacks and Compromises: Notes from Lab, Field, and Factory Floor (PDF), NorthStar Rubber Specialties, L.L.C.