Spanish painter Francisco de Goya's stark portrayals of Spanish aristocrats, intellectuals and fellow artists in a major new exhibition at the National Gallery in London aims to show him as "the best ever portrait artist."

The exhibition, which opens on Wednesday, brings together from around the world around 70 portraits by the celebrated artist who lived between 1746 and 1828.

The works make up almost half of the 150 Goya portraits that still survive today, and account for a third of his total known output.