Leonardo da Vinci self portrait discovered hidden in manuscript

The faint pencil sketch has emerged after being hidden for 500 years in one of the Renaissance genius’s most famous manuscripts, the “Codex on the Flight of Birds”, written between 1490 and 1505.

It is thought that Leonardo first made the drawing in the 1480s, then later reused the same piece of paper when he came to write his codex - a Latin term for manuscript - on bird flight. LINK