The transitional stage between moving out of your parents' house before finding your forever home is something many of us never grow out of.
READ: Kate Middleton and Prince William's £100/week uni home is worlds apart from Kensington Palace
Living with friends or siblings is considered somewhat a rite of passage before 'proper' adulthood, whether you're plunged into halls at university or choose to split the rent with housemates - but did you know royalty sometimes do the same?
WATCH: Prince William & Kate Middleton return to the university where love struck
From the Duke and Duchess of Cambridge's university flat before they were an item to Princess Beatrice and Princess Eugenie's plush London home, here are all the details on the royal roommates you never knew lived together…
SEE: 10 royal halls of residence: Where Kate Middleton, Prince Charles and more lived at uni
MORE: Kate Middleton and Prince William's secret country home is the perfect love nest
Kate Middleton & Prince William
During their time at St. Andrew's University, Prince William and Kate Middleton originally stayed in halls of residence St. Salvatore’s Hall, known as Sallies. The duo moved just five minutes away to 13A Hope Street in their second year along with two of their friends - where it is believed their romantic relationship bloomed.
At the time, they rented the Victorian townhouse for £100 per week each (a total rent of £1,600 per month), but it would now set tenants back around £3,500 per month.
Kate Middleton & Pippa Middleton
Before the Duchess of Cambridge became a member of the royal family, she shared an apartment on Old Church Street in Chelsea, London, with her sister Pippa Middleton.
LOOK: Kate Middleton and sister Pippa's £1.88million flat they lived in for free
While in their twenties, the party girl sisters loved to spend their weekends dancing in nightclubs across London's most affluent areas. Including the legendary Mahiki and trendy Boujis, a club in South Kensington where a young Kate and Prince William often made an appearance during the earlier years of their relationship.
Princess Eugenie & Princess Beatrice
An official royal residence might be worlds away from your average university halls, but sisters Princess Eugenie and Princess Beatrice lived together at St James' Palace in their twenties before they married their respective partners, Jack Brooksbank and Edoardo Mapelli Mozzi.
The sisters shared the chic four-bedroom apartment for several years, and while they were originally living there rent-free, in 2012 it was decided that they would be required to pay rent on their living quarters.
Prince Harry & Prince William
Royal brothers Prince William and Prince Harry grew up together, so it made sense the duo took advantage of their close relationship in early adulthood, choosing to rent together while training for their helicopter licenses.
In 2009, William, then 27 and Harry, 24, rented a cottage while training at the Defence Helicopter Flying School near RAF Shropshire.
In an interview, William teased his brother's living habits. "Harry does the washing up, but then he leaves most of it in the sink and then I come back in the morning and I have to wash it up. I do a fair bit of tidying up after him," said the Duke.
"He snores a lot too. He keeps me up all night," he added.
Lady Amelia Windsor & Lady Marina Windsor
Lady Amelia Windsor's humble London home is every wannabe It-girl's dream abode. The model, who is 38th in line to the throne shares her chic flat in upscale Notting Hill with her sister Lady Marina, while her family home is in Cambridge.
Amelia's home exudes a retro feel, which she previously told House & Garden was a reflection of her affinity for collectables.
SEE: Prince William's cousin Lady Amelia Windsor's 'small' London flat share – see inside
"We have things that we've collected over the years and beautiful trinkets alongside treasures which I've found in Portobello and Golbourne markets," she said.
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