It's William and Kate's sixth wedding anniversary — here's an iconic image for every year of their relationship

Whether the couple will be marking the occasion by exchanging iron gifts (as is tradition on a sixth anniversary) remains to be seen. But it presents the perfect opportunity to reflect on a relationship, which with the exception of a short break in 2007, has endured more than a decade.

To celebrate William and Kate's milestone, Business Insider has found an iconic image from every year of their relationship. The pair maintained their privacy early on, but are now one of the most photographed couples in the world. This is their story.

William and Kate met at the University of St Andrews and rumours of their relationship began to emerge in 2003.

The pair were first pictured together in March 2004 at the Swiss ski resort of Klosters. William was deeply upset by the paparazzi intrusion and The Sun was briefly banned from royal photocalls after this front page.

Source: The Independent.

Kate and William graduated from the University of St Andrews in June 2005. In 2011, the Middleton family released this image of the pair looking loved up after their graduation ceremony.

In December 2006, Kate was pictured with her parents watching William take part in The Sovereign's Parade at The Royal Military Academy Sandhurst. It was her most significant appearance in their burgeoning relationship.

The couple split in April 2007, but only after being pictured at a Twickenham rugby match together in February. By June that year, there were reports the pair were dating again.

Source: Daily Mail.

Kate watched as William qualified as an RAF pilot at RAF Cranwell in 2008. It was their first public appearance together since The Sovereign's Parade in December 2006.

The pair did not attend any formal engagements together in 2009 and largely kept out of the public eye. In the same year, William visited Australia and New Zealand.

William proposed while on holiday in Kenya in 2010. It was announced a month later by Clarence House, when images of the couple were beamed around the world.

Kate and William married on 29 April, 2011.

The Olympics came to London in 2012. The Duke and Duchess of Cambridge attended many events to cheer on Team GB. In these famous images, they celebrated cycling success in the Velodrom.

A year later, the couple emerged from the Lindo Wing of St. Mary's Hospital clutching their first child, Prince George.

The Duke and Duchess of Cambridge have met many world leaders on their state visits. In 2014, they sat with French President François Hollande at the ceremony of remembrance for the 100th anniversary of the outbreak of World War I.

Prince George waved to crowds at the Trooping The Colour parade at Buckingham Palace in 2015. Just a month earlier, Kate gave birth to Princess Charlotte.

Back on the ski slopes in 2016, William and Kate posed for the cameras after exchanging fire in a snowball fight.

As the pair prepared to celebrate their sixth wedding anniversary, they officially started the London Marathon in April 2017.