A number of Paul Allen’s properties have come up for sale since his death in October of 2018. While his Santa Fe retreat remains for sale, those that have gone to new owners include Enchanted Hill, which sold to Eric Schmidt for $65 million this past winter, and his engaging house in Atherton, California, which closed at $35.3 million in 2020.

Very soon, the artworks that distinguished Allen’s residences will be joining them on the market: after being collected and appraised, the Microsoft co-founder’s art collection will go to auction later this year. The works in the collection represent a time span of 500 years.

Before the first item has even been announced, the sale has already set a record: as the largest private single-owner art collection auction in history. By the time it’s all over and the dust has settled, the 150 items could add up to over a billion dollars’ worth of revenue. Proceeds are earmarked for charitable causes.

The auction will be held at Christie’s New York sometime in November.