In 2001, William and Kate met at the University of St. Andrews. Could they have predicted at the time that they would one day become the most popular couple of the UK? Probably not. Although they both studied art history and had common interests, they were just good friends at the beginning. They even shared a flat in a student house, with two other flatmates.

The first son of Prince Charles and Princess Diana, William was born on June 21, 1982. The Duke of Cambridge is second in the line of succession to the British throne, after his father, which made him one of the most sought-after bachelors of nobility when he was growing up.

Kate Middleton was born nearly half a year before William. Kate's parents, a flight dispatcher and a flight attendant, started their own party supplies business, from which they made a fortune. That's how they could afford to send their daughter to the best schools.

A key moment in William's and Kate's love story was a charity fashion show at St. Andrews in 2002. Kate strode down the catwalk in a see-through lace slip that caught William's eye. They became a couple in 2003. Nine years later, the iconic dress was auctioned for 78,000 pounds (nearly 90,000 euros, $101,000).

It happened in 2010: William proposed to Kate during a holiday in Kenya - presenting an 18-carat sapphire white gold ring encrusted with 14 diamonds. Beyond its material value, the ring has a strong sentimental value: It previously belonged to William's mother, Diana, who tragically died in 1997. The prince said that through the ring, his mother wouldn't miss out on his wedding day.

According to star photographer Mario Testino, this well-known engagement photo of the couple was taken by coincidence. After a two-hour shoot, Testino still didn't feel he had the perfect picture. As the fiancés were about to leave, they hugged in front of a radiator. Testino's snapshot of their spontaneous and genuine embrace went around the world.

On April 29, 2011, William and Kate finally exchanged their vows. Her elegant 1950s-style dress was a real eye-catcher. Her veil was 2.7 meters (8.8 feet) long - five meters shorter than the one worn by Princess Diana. Kate Middleton then officially became Catherine, Duchess of Cambridge.

Two families were turned into one: After the wedding, the Windsors and the Middletons gathered for an official portrait in the Throne Room at Buckingham Palace.

He looks just like his father: Little Prince George was born on July 22, 2013, at St. Mary's Hospital. It was the first time in a century that three successors to the throne were alive at the same time: Charles, his son William and his grandson George, who's pictured here at Pippa Middleton's wedding in May.

On May 2, 2015, nearly two years after Prince George was born, London's Tower Bridge was lit up in pink to announce the birth of William and Kate's daughter, Charlotte Elizabeth Diana. The Royal Artillery Band played Stevie Wonder's song "Isn't She Lovely," and just like for her brother's birth, celebratory cannons were fired. The princess is already over a year old on this photo.

Former US President Obama didn't miss the opportunity to shake hands with the blue-blooded offspring. Appearing somewhat shy, George welcomed him in his bathrobe. Barack Obama and his wife Michelle offered him a special present for his birthday: a toy dog, a replica of the Obamas' pet Bo.

During their seven-day tour of India in 2016, William and Kate were given a traditional welcome at the Banganga Water Tank in Mumbai, where they let flower petals float. During their stay, they also participated in a game of cricket and went to visit a slum in Mumbai.

The young royal family is definitely charming. That's why Foreign Minister Boris Johnson incited the couple to travel to Europe to symbolically extend a "hand of friendship" as Brexit negotiations begin. During their first joint state visit to Germany on July 19, even their cute children will be contributing to the charm offensive.

William and Kate, along with their two children, landed in Berlin Wednesday as part of their four-day tour of Poland and Germany. The visit has widely been reported as an attempt to shore up ties with the EU as Britain prepares to make a bitter exit from the bloc. Their children, Prince George and Princess Charlotte did not take part in any of the official visits.

Crowds waving small Union Jack flags gathered by Berlin's iconic Brandenburg Gate to greet William and Kate. It would be the young royal couple's only public appearance that day. The Duke and Duchess of Cambridge spent about a quarter of an hour shaking hands and speaking to locals.

The Duke and Duchess of Cambridge met with German Chancellor Angela Merkel for lunch. While the political content of their talks were not disclosed, a source close to the chancellor did reveal what was on the menu. Britain's royals were treated to three kinds of fish: salmon and tuna as a starter and cod with a side of vegetables for the main course.

The royal couple visited Berlin's Holocaust memorial, guided by the head of the Foundation Memorial to the Murdered Jews of Europe, Uwe Neumärker. There, William and Kate also met with Holocaust survivor Leon Schwarzbaum. "It was very moving," William said of the visit. The couple also visited the site of the Nazi concentration camp at Gdansk during their visit to Poland a day earlier.

William and Kate visited children from the East Berlin Strassenkinder charity, which supports vulnerable young people. They then met with Teresa Enke, whose foundation raises awareness about depression after the suicide of her late husband, footballer Robert Enke. William and his brother Harry have spoken of the trauma they suffered following the death of their mother, Princess Diana, in 1997.

The royal couple where the special guests at the residence of the British ambassador in Berlin later in the evening where they celebrated the 91st birthday of William's grandmother, Queen Elizabeth II. The next morning, they took off to Heidelberg, a town that is twinned with Cambridge, where William and Kate were expected to watch the boat race on the Neckar river.

The Royal Couple started their second day in Germany at the German Cancer Research Center in Heidelberg, where they learned about research projects focusing on particularly aggressive strands of leukemia. They were accompanied by the Baden-Württemberg state premier, Winfried Kretschmann.

The Duke and Duchess of Cambridge went on to take a tour of Heidelberg's central market square, where they were instructed on how to make the perfect pretzel. Onlookers were amused as the couple tried their hands at baking. It's probably best they don't give up their day jobs.

William and Kate raised their beer mugs after the boat race between Cambridge and Heidelberg - two of the world's most elite universities. Kate changed into a more sporty outfit for the unique event, which attracted young and old to the Neckar river. But before they could drink up, the young couple were on their way back to Berlin - for a reception at the legendary "Clärchen's Ballhaus."

The next morning, William and Kate got ready to take a high-speed ICE train to Hamburg as the last stop of their tour of Germany. Security was high at Berlin's central train station as the royal couple took off to the Hanseatic city, where their first stop was the Hamburg Maritime Museum, which houses a small-scale replica of the decommissioned Royal Yacht Britannia.

After the Maritime Museum Kate and William headed to the Elbphilarmonie Concert Hall to witness a performance by the Hamburg Symphony Orchestra. Kate even got to try her hand at directing. The new performance space had only been inaugurated earlier in the year and towers over Hamburg as the city's newest landmark.

The couple went on to tour an Airbus training facility in Hamburg, where they witnessed the latest innovations in the field of aviation. The Duke and Duchess of Cambridge witnessed the assembly of A320 jets at the facility and learned how virtual reality was used in engineering today.

After three action-packed days in Germany, William and Kate returned to Britain but not before this priceless photo opportunity. The couple's children, George and Charlotte, had been kept out of the limelight for almost the entire duration of the visit. The little heirs-to-the-throne waved as they headed back home in time to celebrate Prince George's fourth birthday on Saturday.