(Image credit: Royal Collection Trust)

The British Royal Collection, the largest private art collection in the world, is undergoing an extensive survey that is expected to take a decade to complete. Queen Elizabeth's 7,500-plus oil paintings will be condition-checked, cleaned, and photographed, starting with the "lesser palaces," such as Balmoral in Scotland, this summer.

Queen Elizabeth’s Majestic Art Collection To Get Royal Spruce-up | Artnet