Darren Cahill has announced the end of his four-year coaching relationship with world No.1 Simona Halep.
The highly regarded Australian guided Romanian Halep to the top of the rankings and to a long-awaited grand slam title this summer when she won the French Open in her fourth slam final.
Announcing the split on Instagram, Cahill said he wanted to spend more time with his family and would be taking a year off from coaching.
"I would like to announce that Simona and I will not be continuing our partnership in 2019 purely for family reasons on my part," Cahill wrote.
"After much thought and discussion, and many years with 30-plus weeks on the road away from my family, I've decided to take a 12-month break from coaching to be home more for support as our children enter important stages of their lives with the final year of high school, sports and college preparations all becoming more time-consuming.
"I'd like to thank Simona for the last 4 amazing years. Her understanding, personality, work ethic, generosity and professionalism made it a pleasure to stand by her side as her coach.
"She's a young woman of total class and someone I respect greatly which is something more important than any result achieved. Basically, I had the dream job and I want to thank her for making it that way, and the opportunity to work with someone so talented and dedicated.
"I wish Simona and her team nothing but continued success and I look forward to supporting her from the sidelines next year."
Cahill and Halep were seen as having one of the closest coaching relationships on tour, although it was not always smooth sailing.
Cahill was so unhappy with Halep's negative attitude during a loss to Johanna Konta in Miami last year that they briefly parted, although he was back in her corner a month later.
Halep wrote on Twitter: "Thank you so much @darren_cahill for all your hard work and incredible support over the past four years. I was lucky to have you and what a journey we had. Wishing you and your family nothing but the best and I'm sure I'll see you soon!"