News lead: A rule introduced in 1993 by the UK government protected the royal family’s assets from being wiped out if two monarchs died within a short period of time, Business Insider reports.

The Queen Mother died 20 years ago in 2002, exercising the first part of the provision.

By the numbers: Charles inherits the Duchy of Lancaster fortune, which generated $27 million in revenue for the Queen last year.

The Crown Estate, estimated to be worth more than $34.3 billion in assets, will now belong to Charles III, CBS reports. Prince William, Charles’s eldest son, inherited the $1 billion Duchy of Cornwall fortune from him.

Why it matters: The royals don’t have to pay the 40% levy on properties worth more than $377,000, while the electorate does.

However, the Queen began paying income and capital gains tax on the estate in 1993 of her own accord. Charles may decide to do the same.