It’s new beginnings and life changing moments in the season three premiere of Ladies of London. Julie Montagu and her husband Luke officially take over his family estate, Mapperton, and the responsibilities of its 400 year legacy. Meanwhile, Marissa is pregnant with her third child, but the birth is far from a joyous event due to a life threatening condition. Caroline Fleming struggles to balance home life as she has to travel to Denmark weekly to spend time with her sick father. While, Sophie, Caroline's sister-in-law, finds herself caught in the middle of a feud between Julie and Caroline Stanbury.

In the aftermath of Sophie's divorce party, it's Stanbury vs. Stanbury when Caroline and Sophie battle it out over family loyalties. Julie tries to makes big changes at the family estate, Mapperton, but with nearly 400 years of British history behind it, she doubts herself as an American. Marissa welcomes her new baby after facing her near death experience in surgery. Meanwhile on a trip to Denmark with Juliet, Caroline Fleming makes the ultimate red carpet slip up landing her in red hot water with her family.

In the aftermath of her press slip up in Denmark, Caroline Fleming seeks help from her therapist to work through the tension between her and her family. Marissa must cancel her party when baby Sadie gets sick and is rushed to the hospital. Meanwhile, Julie looks forward to hosting all the ladies at the family estate, Mapperton, but with tensions mounting between Caroline Stanbury, Sophie, and Adela things come to a head when the house rules are laid down.

Julie is put to the test as Lady of the Manor when her first dinner party explodes into an argument resulting in Caroline Stanbury storming out. A day fishing on the water does nothing to wash away the tensions as Caroline Stanbury's relationship with Sophie continues to fracture over loyalty. Meanwhile Caroline Fleming and Juliet gossip about Marissa's choice to leave her baby behind in London for a party in the Hampton's.

Julie deals with more dramatic life changes as her daughter picks dresses for Leaver's Ball and prepares to leave for University. Sophie continues to question her feuding relationship with her sister-in-law Caroline Stanbury. Meanwhile in Denmark, Caroline Fleming deals with the legacy and burden of her family estate, Valdemar's Slot. Eager to get back to normal, Marissa throws a cocktail party, but when Adela and Caroline Stanbury confront each other the party ends in tears.

It's the Queen's birthday in London and the ladies celebrate around the town! On the West Side Marissa and Sophie head out to have a ball at ping pong, but end up rediscovering their wild sides. Meanwhile, Juliet asks Caroline Stanbury and Caroline Fleming to join her on the East End for a trendy pub crawl, but their happy hour is ruined when bickering ensues. Marissa and Juliet confront each other about gossiping while Sophie and Caroline Stanbury decide to finally have it out.

In an effort to reconnect with her friends before her big move to Dubai, Caroline Stanbury takes all the ladies on trip to Scotland. Staying in a 15th-century castle Caroline Felming feels right at home, but the "no rules" itinerary puts Julie on the defense. Meanwhile, Sophie continues to pledge her loyalty to her family over friends. Marissa is confronted over starting the rumors about Caroline Stanbury's legal issues and Adela opens up about her troubled past.

The whiskey is flowing and the haggis is hot as Caroline Stanbury's castle getaway with the ladies in Scotland continues. After being confronted over her negativity, Juliet makes an effort to reign in her fiery temper when it becomes apparent Marissa is struggling with her health post-birth. In an attempt to have fun, Caroline Fleming organizes an innocent game with balloons that quickly becomes X-Rated. Sophie witnesses an end to the long standing feud between Julie and Caroline Stanbury, but may have triggered a new one herself.

The ladies head to a high society rowing event, The Henley Royal Regatta, but the fun takes a dive when Adela confronts Juliet over her constant negativity. Meanwhile, Julie takes Sophie to task over her loyalty to family before friends. In an attempt to connect with her past, Caroline Fleming decides to revive an old family tradition. Marissa consults a doctor regarding her health, while Caroline Stanbury keeps a stiff upper lip when her mother deals with her father's health crisis.

Adela, Caroline Stanbury, and Sophie share a slumber party in commemoration of Caroline's last week in London. Julie gets emotional preparing her daughter for the final school dance while Juliet revisits her past and her Polish heritage when her mother arrives to visit. All the ladies come together when Caroline Fleming throws a Midsummer's Eve themed party in honor of her mom, but when a secret is exposed the celebration becomes a nightmare.

Marissa makes a decision about the future of her family while Julie must face the fear of letting her daughter go. Caroline Fleming gets news about her first English language cookbook and Sophie comes to the decision to tell her kids about her separation. Juliet celebrates a milestone in her blogs success, and the ladies gather at a goodbye party for Caroline Stanbury.