John James Audubon’s immense, four-volume The Birds of America comprises 435 individual hand-coloured plates which were issued on subscription in the UK between 1827 and 1838. One of the original subscriptions was taken out by George IV and continued after his death by Queen Adelaide, wife of his successor William IV. This set was bound c.1840 by John MacKenzie of London and has remained in the Royal Library, Windsor Castle ever since. Over time the combination of poor quality leather, the volumesʼ weight and their particular sewing structure, together with frequent usage, had rendered them unsafe to handle. This presentation will describe the complete conservation and rebinding project successfully undertaken in the Royal Bindery to return them to use.