The Duchess of Sussex has, for the first time since she married Prince Harry, ventured out with the Queen as an official member of the Royal Family. After an unprecedented night on the monarch's personal train, Meghan Markle was invited to complete a series of joint engagements with her new grandmother-in-law in Cheshire.
The outing put her firmly in the public eye as a royal in her own right, but also opened her to scrutiny from her new relative, who abides by strict etiquette rules. From the style of her dress to the way she sits, the Duchess must now follow protocol to a tee.
At the start of the trip, which otherwise went smoothly, the Duchess had a moment of hesitation when getting into the car to depart Runcorn station. Meghan initially stood back to allow the Queen climb into the car before her. But she then realised they were standing on the driver's side of the vehicle and paused to ask her Majesty, "What's your preference?"
Although official protocol says the monarch should sit diagonally to the driver and go ahead of others when entering a vehicle, she is known to prefer sitting behind her driver. The 92-year-old indicated that Meghan, who was flustered, should climb into the car ahead of her. In doing so, the new Duchess presented her back to the Queen: another royal faux pas.
Despite the blip, the Queen appeared to enjoy her day with the Duchess, laughing and talking as they watched children perform.
Here are some of the other rules the Duchess will have been advised to follow on her day with her Majesty.
Follow the royal dress code
The Royal Family abide by a strict code that says they should dress modestly and for the occasion. The Duchess opted for a cream Givenchy dress, with a hem below the knee and shoulder cuff, while the monarch wore a lime green outfit from Stewart Pravin. The Duchess will have been advised to dress in a colour less bold than the Queen's, as she likes to stand out so the public can see her. Meghan will also have been told to avoid wearing an outfit with a short skirt or one that displays cleavage.
The Duchess paired her outfit with nude nail varnish, pantyhose and simple jewellery, as is expected for daytime events. She opted not to wear a hat or gloves, both of which were donned by the Queen. Princess Diana first broke the hat and glove protocol, paving the way for royal women not to have to wear the accessories.
Updating her style to fit her new role, the Duchess wore her hair down with a sleek blow dry, rather than pulled back in a messy bun.
Do curtsy when you see the Queen
Royal etiquette dictates women must curtsy and men bow to the Queen the first time they see her every day. For the Duchess, this will have been on the royal train in the morning, before they embarked on the day of joint engagements. A low and slow curtsy is recommended for addressing the monarch.
Meghan is expected to curtsy to all royals of a higher rank to her, which includes the Queen, the Duchess of Cornwall and the Duchess of Cambridge.
The first time she saw the Queen today, Meghan will have called her Your Majesty. Following that, she will have addressed her as Ma'am when other people could hear and by the family's intimate address Mama when they couldn't.
Don't walk in front of the Queen or turn your back on her
The Royal Family must walk in line with their rank, which means no one should walk in front of the Queen. Prince Philip always walks three paces behind her, a protocol the Duchess followed throughout the day.
Following this, it is considered rude to present the Queen with your back, and most people will walk backwards away from her. Meghan did turn her back on the monarch when entering the car, but avoided doing so again.
Don't touch the Queen or ask personal questions
The Duchess of Sussex will, no doubt, form an intimate relationship with her Majesty over time. But she will also have to set an example in her public interactions with the monarch. This includes staying out of her personal space: etiquette says no one should touch the Queen or ask her personal questions.
Michelle Obama broke this code in 2009 when she put her arm around the Queen. Never one to be rude, her Majesty returned the favour and put an arm around Obama's back. Learning from the mistakes of others, Meghan was careful to address the Queen closely while keeping her hands tucked in.
Do take the Queen's lead
Members of the public and royal family are expected to take the Queen's lead in most cases. They should only speak after she has spoken to them, sit once she has and start eating when she takes the first mouthful.
This rule carries in private too. As such, the Duchess would have been expected to wait for the Queen to retire to her carriage on the royal train before turning in herself. It has been reported that her Majesty often goes to bed at midnight.
There are a couple of instances when this rule is reversed. The first is when arriving at a location. This didn't apply to Meghan, who arrived in Chester alongside the Queen. But, as a general rule, the monarch must never be kept waiting.
The second is at the end of a meal. Once the Queen has finished eating, everyone else's plates will be taken away regardless of whether they are done or not. That makes it advisable for the hungry to finish their meals before her Majesty does.
Always sit like a royal
Rules dictate that royal women should keep their legs together and never cross them at the knee. Meghan has mastered what is called the "Duchess slant", a way of sitting fashioned by Princess Diana, which involves crossing the legs at the ankle and tilting them slightly to one side. As well as giving one a modest posture, it makes the legs look longer.
Eat like a royal
Royals are encouraged to avoid shellfish wherever possible and stick to easy-to-eat items. They must hold their knife in the left hand and fork in the right, keeping the prongs of the fork pointing downward at all times. This means food must be balanced on the back of the fork. If a guest wants to leave the table, they should use a polite, "Excuse me", with no further detail.
At the end of the meal, when tea is served, the teacup must be held with the index finger above the handle, one finger through the ring and the third supporting it. Contrary to popular belief, the royals don't prick their pinkies.