The bird was originally called the Redbreast or Ruddock (from the Old English word for red). In the Middle Ages, it was given the nickname "Robert" or "Robin", just as the wren was later called "Jenny". It was mistakenly thought that only the cock had a red breast, and that wrens were female robins. So there was a popular saying: "'The robin and the wren are God Almighty's cock and hen."
 

In fact, both cock and hen robins have red breasts, for both sexes are territorial, using their vivid breasts as threat displays to scare away intruding birds. The hen defends her own territory in autumn and winter, and the territory she shares with her mate in spring and summer. She is just as aggressive a fighter as the cock robin.

The most important thing for any robin is its territory, which serves as a supply of food for the bird and its young and, for the cocks, a place to attract mates. To defend their territory, cocks and hens will fight and sing almost all year round, falling silent only in July and August when they moult.

Warbling song

The bird's song is high, clear and varied, with trills and sweet wistful notes. Such is the beauty of the song that robins were often trapped and kept in cages as songbirds, leading William Blake to write, "A robin-redbreast in a cage/ Puts all heaven in a rage". Read more about William Blake here.

The robin is one of the few British birds to sing in autumn. So John Keats, in his Ode To Autumn, wrote that "now with treble soft/The redbreast whistles from a garden croft."  The song continues but grows weaker as winter draws in.

William Cowper described this in his poem A Winter Walk At Noon:

The redbreast warbles still, but is content
With slender notes and more than half suppressed.
Pleased with his solitude, and flitting light
From spray to spray, where'er he rests he shakes
From many a twig the pendant drops of ice,
That tinkle in the withered leaves below.

Courtship

In late December, males begin to sing loudly in their territories to attract females, who leave their own territories to seek a mate. It is the hen who chooses the cock, and she may visit a number of territories before making her choice. The instinct to defend its territory is so strong that there is usually a brief fight between cock and hen before he accepts her presence. The two birds then share the territory while the cock courts the hen by repeatedly feeding her.

Nest building

After a month or more sharing their territory, the hen, working on her own, builds a cup-shaped nest in any available hollow, using moss and dead leaves. Robins have been recorded nesting in many strange places:

"At intervals robins acquire notoriety by nesting in a jam jar, a letter-box, an old boot, a pulpit, a human skull, or even a dead cat. A Birmingham pair started to build their nest in an unmade bed... When the owner realised what was happening, the bed was left unmade, and the birds eventually reared a family from it. The record for speed goes to a Basingstoke pair. A gardener hung up his coat in the tool shed at 9.15 a.m., and when he took it down to go off to lunch at 1p.m. there was an almost complete robin's nest in one of the pockets."

David Lack, The Life Of The Robin, 1965

Once the nest is built, mating takes place. Between March and June, hens lay clutches of five or six eggs, which are white with red speckles. While the cock continues to feed her, the hen incubates the eggs for five to six weeks until the young hatch. Young birds leave the nest after about two weeks, and then a new clutch may be laid. After the last of the young have been raised, cock and hen will separate. The following year, each may find a new mate, or they may be reunited. Few robins seem to pair for life.

The young are brown with golden spots, whose breasts gradually redden from July. Although adults may live up to ten years, three-quarters of robins will die in their first year, mostly the victims of pet cats and cars.

Tameness

Since the 14th century, when Geoffrey Chaucer wrote of the "tame ruddock", English robins have been noted for their tameness. No other bird will feed as readily from the hand. Robins are very different on the continent, where they remain a shy woodland species.

The tameness of the robin has often been mistaken for friendliness. So Isaak Walton described "the honest robin who loves mankind". In fact, the robin, unlike a parrot or a raven, will not be made a pet. The reason is that ravens and parrots are naturally social, while robins are solitary and aggressive. Their willingness to feed from our hands is just another sign of their fearlessness.