Royal family member Peter Phillips chose a "timeless" engagement ring to propose to his now fiancée, Harriet Sperling, that is worth upwards of $20,000 AUD.

Princess Anne's son releases a photo to announce his engagement to Harriet Sperling.

"Mr. Peter Phillips, the son of HRH The Princess Royal and Captain Mark Phillips, and Ms. Harriet Sperling, daughter of the late Mr. Rupert Sanders and Mrs. Mary Sanders of Gloucestershire, have today confirmed their official engagement," spokesperson Gerard Franklin told Hello! in a statement.