The British Museum announced on Tuesday it had acquired an exceptional set of Pablo Picasso's "Vollard Suite", comprising 100 etchings produced by the artist between 1930 and 1937. Complete sets of the suite are very rare, held only by a handful of museums in the world including the National Gallery in Washington, the Museum of Modern Art in New York and the Picasso museum in Paris. The series shows Picasso's developing interest in sculptural forms and moves from neoclassical images of him and his lover, Marie-Therese Walter, to darker, violent and more sexual themes. It is in the etchings that he first introduces the Minotaur, the half-man, half-animal which later appears in his ground-breaking painting "Guernica" displaying the horrors of the Spanish Civil War. The series "is on the road to Guernica", explained Stephen Coppel, curator of modern prints and drawings at the British Museum in London at a press launch. "It is the most important series from Picasso. They are remarkable because of their versatility and inventiveness." The etchings are named after Ambroise Vollard, a Paris art dealer and print publisher who gave Picasso his first exhibition in the French capital in 1901. He commissioned the suite in exchange for two paintings by Cezanne and Renoir. Some 310 sets were printed and after Vollard's death in 1939 they passed to another dealer, Henri Petiet. The British Museum bought its set from Petiet's heirs, paying about £1 million (1.17 million euros, $1.56 million) for them. The suite will be on display from May 3, 2012, until September 2, 2012, alongside examples of classical sculpture that inspired Picasso, as well as etchings by Rembrandt and prints by Goya which also influenced him.