Duchess Catherine looks effortlessly chic as she channels Princess Diana at the Order of the Garter ceremony

The event also marks 11 years since she made her debut as Prince William’s girlfriend!

Just days after stepping out in a breathtaking white, off-the-shoulder Barbara Casasola dress for a gala dinner, the Duchess of Cambridge has wowed us once again.
This time, the royal mum-of-three opted for a chic black and white coat dress while attending the prestigious Order of the Garter ceremony at Windsor Castle on Monday.
A royal show of support for their husbands. (Image: Getty)
Choosing the Catherine Walker "Liza" white coat dress complete with black trim, she paired the elegant number with a black Lock & Co. hat, a matching clutch and black laser-cut Prada heels, but her outfit for the day also reminds us of an outfit once worn by another very fashionable royal – her late mother-in-law Princess Diana.
The outfit in question was the white three-button skirt suit with navy piping worn by the late Princess of Wales in 1995 for the VJ Day 50th anniversary celebrations, to top it all off, Kate completed Monday's outfit with pearl drop earrings which once belonged to Princess Diana too.
Kate's outfit on Monday had a striking resemblance to an outfit worn by the late Princess Diana in 1995. (Images: Getty)
Standing alongside Queen Maxima of the Netherlands, the Duchess of Cornwall, Queen Letizia of Spain and the Countess of Wessex, Kate watched on proudly as Prince William walked in the Garter Day procession, donning a velvet robe, insignia and a plumed hat.
Garter Day is also a particularly special day for the Duke and Duchess of Cambridge as each year the occasion marks another year since Kate made her official public debut as Prince William's girlfriend back in 2008, and also happened to be the year William received his Order of the Garter knighthood.
Duchess Camilla, Queen Maxima of the Netherlands and Duchess Catherine watch as Prince William walks past in the Garter Day procession. (Image: Getty)
Kate and William met while studying at the University of St Andrews and Kate's appearance at the event 11 years ago was a clear sign she was being welcomed into the royal fold. The couple tied the knot three years later on April 29, 2011 at Westminster Abbey.
At her first public appearance the future Duchess opted for a black and white polka dot skirt suit with a matching hat, and clearly looked comfortable alongside members of the royal family, laughing and chatting with Prince Harry and the Duchess of Cornwall.
Kate already looked incredibly comfortable at Garter Day in 2008, chatting away with Prince Harry and the Duchess of Cornwall. (Image: Getty)
The Order of the Garter is the oldest and most senior Order of Chivalry in Britain, set up by King Edward III almost 700 years ago, after being inspired by tales of King Arthur and the chivalry of the Knights of the Round Table.
While it was once limited to males and members of the aristocracy, today the Knights are both male and female and are chosen from a variety of backgrounds in recognition of their public service, however the number of members is strictly limited - it includes the Sovereign, The Prince of Wales, members of the royal family and only 24 members (foreign members also do not count towards the overall 24).
Each year in June the annual Garter Day procession takes place at Windsor Castle and is the day The Queen formally invests any new Companions with the Order's insignia in the Throne Room.
This year's new appointments to The Garter include athlete Lady Mary Peters, the Marquess of Salisbury, a former Chairman of the Thames Diamond Jubilee Foundation and King Felipe VI of Spain as a Supernumerary (a "stranger" member of the Garter) along with King Willem-Alexander of the Netherlands.
Following the investiture, The Queen entertains members and officers for lunch before taking part in a procession on foot to St George's Chapel before the new Companions are installed in a short service.
In exception to being a member of the Garter (which has a strict number of members its limited to), the Royal Victorian Order is the highest knighthood that can be awarded at the sole discretion of the Monarch - there is also no limit to how many people can bestowed the honour.
The Queen's State Banquet held for US President Trump's visit earlier this month marked the first time the Duchess wore her Royal Victorian Order blue, red and white sash.