He said: “I’m very gamekeeper, because the Royal Collection generally doesn’t borrow, we lend, whereas the Royal Academy is almost entirely poacher, so we sort of understand it from both points of view.”My presence there reminds colleagues in other institutions that the Royal Collection has in the past been a generous lender. “No institution would do a reciprocal arrangement, but we have in the past been very generous, for which these institutions are very grateful.” Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings. Many of the pieces were regained by Charles II following the restoration of the monarchy in 1660, but some of them have never come back to England. Some of the most celebrated pieces include four Mortlake tapestries of Raphael’s Acts of the Apostles which have been kept in the Mobilier National in Paris.Two Titian pieces have also been retrieved, the Supper at Emmaus, from the Louvre in Paris, and Charles V with a Dog, from the Museo del Prado in Madrid. Desmond Shawe-Taylor, Surveyor Of The Queen’s Pictures, said he and Per Rumberg, curator of the RAA, had not had any trouble persuading the foreign curators to give up the paintings.He said: “The key thing in any negotiation is really to remember that the person making the decision is also a curator, and is therefore as enthusiastic about curatorial projects as the person asking for the loan.”All the curators that we spoke to were fascinated by the subject and therefore found themselves personally as scholars inclining toward the loan.”He added that the Royal Collection’s previous generosity had persuaded some museums to relent. Queen Henrietta Maria with Sir Jeffrey Hudson, 1633, by Sir Anthony van Dyck, which is in the new exhibition Charles I: King and CollectorCredit:Anthony van Dyck/Royal Academy of Arts/PA Wire He had been a prolific collector of art, amassing 2,000 pieces including 1,500 paintings and 500 sculptures, dating from the fifteenth to the seventeenth century. But just months after his execution, the King’s collection had been scattered across Europe by his successor Cromwell, offered for sale and as diplomatic gifts to foreign states. The exhibition will run in tandem with a display of the arts bought and commissioned by Charles II, at the Queen’s Gallery, in Buckingham Palace, which will run from December to May. The BBC is also planning a four-part TV series to be broadcast on BBC Four and presented by Andrew Graham-Dixon, examining the Royal Collection. Among the pieces examined by the art historian will be 4,000 prints and photographs of Raphael frescoes commissioned by Prince Albert in the 19th century. They were confiscated by Oliver Cromwell and scattered all over the world. But some of the most famous pieces in King Charles I’s art collection are set to be reunited for the first time since the 17th century in an exhibition at the Royal Academy of Arts. Curators from the Queen’s Gallery, based at Buckingham Palace, and the Royal Academy, have spent two years travelling Europe to persuade some of its most distinguished galleries to let their art travel back to England. The pieces which are set to return for the exhibition from January until April next year include an image of the King with his horse, which will be shown alongside two other equestrian portraits of Charles I. Van Dyck’s Charles I (Le Roi a la Chasse) which came from the Louvre and will be in England for the first time since the 17th century, is the Dutch artist’s most celebrated portait of the King. Around 20 of the 150 works in the Charles I exhibition are from foreign museums and haven’t been back to the UK since the 17th century when they were sold or sent abroad by Oliver Cromwell. Following defeat in the English Civil War, Charles I was deposed in 1649 and sentenced to death by Parliament on 27 January.