Meghan Markle stuns in a £464 cream linen suit and Princess Diana's £17,800 Cartier watch as she attends high-powered business summit in the Hamptons

Meghan Markle showed she meant business as she joined a host of businesspeople and celebrities alike in the Hamptons.

The Duchess of Sussex, 42, was the epitome of elegance in a trendy relaxed suit from Australian brand St. Agni as she attended the G9 Ventures Summer Summit hosted by power broker Amy Griffin on Saturday.

She teamed a buttoned vest costing £209 with matching £255 trousers in the same beige colour, and paired her ensemble with an array of glittering jewellery - including Princess Diana's £17,800 Cartier watch.

According to Page Six, Meghan had flown into the millionaires enclave by private jet with entrepreneur Jamie Kern Lima, from Santa Barbara. 

Sources told the outlet that she is there to pick up tips on her new lifestyle brand American Riviera Orchard. 

The Duchess of Sussex, who was seen alongside designer Misha Nonoo and cosmetics owner Bobbi Brown, wore a vest and trousers combination by St. Agni

Meghan was pictured alongside fashion designer Misha Nonoo and make-up artist and cosmetics owner Bobbi Brown.

Though her smart outfit cost just shy of £500, her extensive shimmering jewellery collection took centre stage - and boasted a whopping price tag.

Among the assortment of accessorises donned by the Duchess was Princess Diana's £17,800 Cartier Gold Tank Française watch and her £5,800 Cartier Love Yellow Gold Bracelet.

Also adorning her wrist was her Against Evil Eye Five Eye Diamond Pave Bracelet by celebrity-favourite jeweller Lorraine Schwartz.

The now sold out piece, which retailed for a staggering £15,800, features topaz, as well as both black and white diamonds.

On top of her bangles, Meghan also donned two necklaces, including her £15,500 Cartier Justr Un Clou Necklace. She layered it with her £1,425 Imperial Disc Pendant Necklace from Ariel Gordon Jewellery. 

Prepared for the sunny day ahead, Meghan finished off the look with her £175 Santa Barbara Black Frame Sunglasses in Black.

Page Six reported that the annual event is held at the $13 million home (£10 million) of Griffin who shares the property with her husband, billionaire hedge fund manager John Griffin.

American entrepreneur, investor, and media personality Jamie Kern Lima (pictured right) poses with Meghan Markle (pictured left) and Spanx founder Sara Blakely (pictured centre)

Meghan's brand soft launched earlier this year with an official Instagram page and website being set up 

Other stars in attendance included Gwyneth Paltrow alongside Reese Witherspoon and actress Laura Dern. 

Meghan's brand soft launched earlier this year with an official Instagram page and website being set up. 

She will no doubt be using the event to help her brand by soaking up tips for her new brand.

Surrounded by people like Griffin will aid her in doing just that, who according to Wall Street Journal is known for her use of 'soft power.'

This includes making introductions, chasing down founders and offering mentorship. 

She started angel investing in 2014 and launched G9 three years afterward, telling the WSJ: 'There was a moment where I was sitting at a fundraiser thinking, ‘Wait, I can put money into something, see it grow, and use my skill set and help a founder?’.

'And people had said to me, "Why aren’t you doing this full time? You already help people by buying their products and then sending it to everyone."'

Prince Harry, Duke of Sussex, and Meghan, Duchess of Sussex attend the closing ceremony of the Invictus Games in Duesseldorf, last year 

G9 does not lead huge investment but does contribute smaller amounts, from tens of thousands of dollars to several million, according to the WSJ.  

Meghan shared the logo for her company in a 10-second story video while dressed in a black ball gown. 

The clip then showed her wearing a simple white outfit while arranging flowers and cooking in a kitchen.

In April, Meghan sent 50 jars of her strawberry jam to influencers and celebrity friends across the United States.

Award-winning actress and comedy writer Mindy Kaling and actress Tracee Ellis Ross, daughter of Diana Ross, revealed on social media they had been gifted jars.

Each jar was labelled with the Californian American Riviera Orchard branding, and numbered out of 50. The jars were secured with a lid and muslin cloth.

Meghan's brand will reportedly feature 'edible oils and fats', jellies, jams and spreads made of legumes, garlic, and sesame, as well as nut and fruit butters.