The essential guide to the Middletons
The Middletons will be an important source of support for the Duke and Duchess of Cambridge as they get to grips with parenthood. Kate is close to her mother Carole, father Michael, sister Pippa and brother James, while William holds his surrogate family in great affection.
Since William and Kate wed in 2011, the Middletons have been welcomed into the royal fold with open arms. They were invited to sail down the Thames as part of the flotilla for the Queen's Diamond Jubilee and Carole and Michael have joined the Queen's exclusive carriage procession at Ascot.
Such inclusion by the monarchy has rarely been seen for a bride's family in the past, but it is thought the royals are keen to learn from previous mistakes and ensure Kate's transition into royal life is a success.
The Middletons have been embraced by all quarters of the royal family, reportedly also staying with the Prince of Wales and the Duchess of Cornwall at Birkhall on the Balmoral estate.
They will undoubtedly play a key role in helping Kate and William raise their child, offering a stability and normality away from royal households run by servants.
The Duchess is reported to be moving back to spend the first six weeks of her child's life with her parents. Kate was spotted buying a cot with her mother and it is thought Mrs Middleton may help care for the child when her daughter carries out royal engagements.
Carole Middleton has already experienced the full force of public scrutiny, while her daughter was dating William. She became the scapegoat following the couple's brief split amid claims she was "too common" for the Queen and the Duke of Edinburgh.
Deemed pushy, she was criticised for using words frowned upon in royal company, such as "pleased to meet you", "toilet" and "pardon". But in fact Mrs Middleton had not even been introduced to the Queen. She is now said to get on well with the monarch and famously with Prince Philip.
In 2006, she was criticised for chewing nicotine gum during William's passing out parade at Sandhurst. Carole is said to have persuaded Kate to reject her first university choice on hearing the news that William was going to St Andrews, urging her to go there instead, according to an article in The Spectator.
Her former career as an air stewardess is said to have led to mocking by William's circle, who would declare "doors to manual" when Kate was out of earshot. In 1987, Mrs Middleton and her husband Michael founded mail order company Party Pieces which sells children's party paraphernalia ranging from balloons to fancy dress costumes.
Such was the success of the internet company that it made the Middletons into millionaires, with Kate growing up in Bucklebury, a small village near Newbury, Berkshire. Mrs Middleton is descended from a long line of Durham coal miners.
The family suffered scandal in July 2009 when Kate's uncle - Mrs Middleton's brother Gary Goldsmith - was filmed giving hard drugs to an undercover reporter. Mr Goldsmith, who bragged about a holiday William and his niece had taken at his £5 million villa on Ibiza, reportedly chopped up lines of cocaine and offered to set the News of the World journalist up with high-class prostitutes.
He was said to have reformed his ways and was even a guest at the wedding, but in March this year gave an interview to Hello! magazine in which he talked about Kate and William.
Michael Middleton married Carole Goldsmith in 1980 after meeting her while working for an airline. The British Airways flight dispatcher-turned-businessman joined forces with his wife to launch Party Pieces.
Much less is known about Mr Middleton, but the Queen and the Duke reportedly had a soft spot for him after they first met. Mr Middleton, who is one of four siblings, hails from a middle-class background and his father Peter was a pilot after the war.
The family always refused to speak to the press, but when the engagement was announced, they revealed they were "absolutely delighted" and "thrilled". Mr Middleton, wearing an open-necked checked shirt and tweed coloured jacket, said outside their Berkshire house: "We all think (William) is wonderful and we are extremely fond of him."
William is so close to Mr Middleton he is said to refer to him as "dad".
Kate's vivacious younger sister Philippa "Pippa" Middleton gained notoriety as maid of honour at the royal wedding, causing a stir in her figure-hugging bridesmaid's dress. There are websites dedicated to her bottom and she was named as one of Time magazine's 100 most influential people in 2012.
"It's startling to achieve recognition on account of your sister, brother-in-law and bottom," she admitted in her party book Celebrate. Her book was marketed as a one-stop guide to entertaining throughout the year.
But the publication was mocked by some for its over simplistic advice and even sparked a parody Twitter account @PippaTips. She recently became a columnist for Waitrose's monthly magazine, penning a column called Pippa's Friday Night Feasts. But there was an outcry when it emerged cookery queen Delia Smith had been dropped from the magazine, with customers questioning Pippa's expertise.
The middle Middleton sibling is said to be more outgoing than Kate. She shines on the posh party scene and is said to be keen to marry into "old money". Her uncle Gary Goldsmith revealed: "They are different. Kate works really hard at everything. She is brilliant at whatever she turns her hand to, but works at it, throwing herself into everything. Whereas Pip, everything seems to come very easily."
Kate and Pippa were branded the "Wisteria Sisters" - decorative, fragrant and excellent at social climbing. A close pair, they were often spotted holding hands when faced with the paparazzi.
Pippa went to Edinburgh University and shared a flat with Edward Innes-Ker, son of the Duke of Roxburghe, and George Percy, son of the Duke of Northumberland. For three years she dated JJ Jardine Paterson, the son of a prominent Hong Kong banking family, but they split in 2007.
In 2008, she worked for events company Table Talk, but also for Party Pieces on its The Party Times online magazine. She featured in a Christmas special for Hello! magazine in which she shared her tips for entertaining during the festive season. As a party trick, she apparently once took her clothes off, wrapped herself in toilet paper and climbed on top of a human pyramid.
Pippa, who helped Kate with her wedding plans, joined her sister as they lunched with the Duchess of Cornwall and Camilla's daughter Laura Lopes ahead of the nuptials. She previously dated former England cricketer Alex Loudon, but is now dating stockbroker Nico Jackson.
The youngest of the Middleton children, James, went to Marlborough College, like Kate and Pippa, and started at Edinburgh University, but quit in the first year. He set up The Cake Kit Company in 2007 which provides ingredients and decorations for children's cakes and has said he has great childhood memories of his mother baking.
In August 2008, pictures of him at a party wearing a black and white polka dot dress and in a French maid's outfit appeared in a newspaper. He appeared in a glossy spread in Hello! by baking several cakes featuring legendary front pages to mark the magazine's 21st anniversary.
James, who gave a reading at his sister's wedding, has dyslexia and has spoken about the condition to raise awareness on behalf of the British Dyslexia Association. He is romancing TV presenter Donna Air, who starred in the children's TV show Byker Grove.