OK, so they’re not people as such, but the ravens at the Tower of London are renowned the world over.

Known as the “Guardians of the Tower”, there are currently as many as eight ravens living at the tower, lodged in a space on the grass next to the Wakefield Tower.

Legend has it that there must be at least six ravens living at the Tower – should they leave, not only will the Tower fall but the kingdom as well (although we hasten to add that it’s been argued this tradition only started in the Victorian age and that there have been times when the numbers of ravens dropped below the required six, such as at the end of World War II when only one raven remained).

It was King Charles II who first ordered the ravens be protected – an order which must have upset Astronomer Royal John Flamsteed who complained after he found that the birds were interfering with the observation work he was carrying out from the Tower’s north-east turret. He later moved out to Greenwich.

The eight ravens who now live at the tower include Rocky, Merlin, Hugine and the latest additions Jubilee – given to the Tower last year to celebrate the Queen’s Diamond Jubilee – and Grip, named after Charles Dickens’ pet raven.

The birds are looked after by a team of four headed by the raven master, Chris Skaife, who each day feed them 170 grams (six ounces) of raw meat and special biscuits soaked in animal blood.

Not all ravens can cut the mustard to work at the Tower – one recent addition Pearl was apparently bullied by other ravens and had to be withdrawn. And while the birds have the feathers on one wing trimmed to stop them escaping to a new life on the wing, that hasn’t stopped some from doing so including Grog who took off in 1981 and was last seen outside an East End pub.

The oldest raven to ever live at the Tower was Jim Crow, who died at age of 44 in 1928.

WHERE: Tower of London (nearest Tube station Tower Hill); WHEN: 9am to 5.30pm, Tuesday to Saturday, 10am to 5.30pm Sunday to Monday; COST: £21.45 adults; £10.75 children under 15; £18.15 concessions; £57.20 for a family; WEBSITE: www.hrp.org.uk/toweroflondon/.