Marmalade is a sweet conserve made from fruit, sugar and (usually) a gelling agent. In British English the term almost invariably refers to a conserve derived from orangess or from some other citrus fruit. Typically the recipe will include sliced fruit peel and will prescribe a long cooking time in order to soften the peel. Such marmalade is most often consumed on toasted bread as part of a Full English breakfast. The favoured orange variety for marmalade production is a large, sour, late ripening variety originally from Seville in Spain.
In some languages of continental Europe a word sharing a root with 'marmalade' refers to all gelled fruit conserves, and those derived from citrus fruits merit no special word of their own. This linguistic difference has occasionally been claimed as emblematic of the irreconcibility of anglophone and continental world views.
The Scottish city of Dundee has a long association with marmalade. The oft related story of how this came about begins sometime in the 1700s when a Spanish ship with a cargo of Seville oranges, docked in Dundee harbour to shelter from storms. A grocer by the name of James Keiller bought a vast amount of the cargo at a knockdown price, but found it impossible to sell the bitter oranges to his customers. He passed the oranges on to his wife Janet who used them instead of the normal quinces to make a fruit preserve. The marmalade proved extremely popular and the Keiller family went in to business producing marmalade. However this is almost complete fiction. The truth is that in 1797, James Keiller who was unmarried at the time and his mother Janet opened a factory to produce "Dundee Marmalade", that is marmalade containing thick chunks of orange rind, this recipe (probably invented by his mother) being a new twist on the already well-known fruit preserve of orange marmalade.