Kate Middleton's brother James Middleton celebrates his 34th birthday with fiance and new family member

James Middleton - younger brother of Catherine, Duchess of Cambridge - celebrated his 34th birthday  with his wonderful fiancee Alizee and a new family member 'Captain' on Thursday (April 15).

Kate Middleton's brother, who turned 34 on  Thursday, celebrated his birthday in style as he posed with his dog Ella and a new lamb, Captain, inside his land rover.

In his Instagram post, James also paid tribute to Ella for helping him throughout his battles with clinical depression and with the start of his relationship to fiancée Alizée Thevenet.

He wrote a lengthy note to mark his auspicious day: "Today is my Birthday & I'm celebrating with my wonderful fiancee Alizee, and of course all the dogs and a new member of the pack. I always reflect on my Birthday and I'm truly so thankful to Ella for bringing me so much happiness into my life."

paying homage to Ella, Kate's brother penned: "She was the one who introduced me to Alizee, she supported me during my experience with clinical depression, she has kept me young & active and is the driving force behind my motivation to launch @ella.co."

James also  spoke about the new addition to his family, and revealed the heartwarming reason as to why he adopted Captain.

"So you might be wondering why there is a little lamb in the photo," he wrote. "Well, Captain is partially blind & rejected by his mother so we've adopted him…"

James Middleton's comments section was flooded with many congratulatory messages, with Ben Fogle writing: "Happy birthday James."