King Charles III built his own empire long before he inherited his mother’s.

Charles, who formally acceded to the British throne Saturday, spent half a century turning his royal estate into a billion-dollar portfolio and one of the most lucrative moneymakers in the royal family business.

While his mother, Queen Elizabeth II, largely delegated responsibility for her portfolio, Charles was far more deeply involved in developing the private estate known as the Duchy of Cornwall. Over the past decade, he has assembled a large team of professional managers who increased his portfolio’s value and profits by about 50%.