Definition of "livre"

They like to see them awarded comfortable pensions. Is it 700,000 livres a year to the Polignac family?

1992, Hilary Mantel, A Place of Greater Safety, Harper Perennial, published 2007, page 115

He never, it should be noted, totally renounced his inheritance: a critic of the court round, he benefited to the tune of a cool two million livres a year from royal largesse […] .

2002, Colin Jones, The Great Nation, Penguin, published 2003, page 30