Imagine the impact of seeing for the first time 200 choice works from our own National Gallery together with key loans from another collection in one exhibition. Imagine this, and you get close to what it’s like seeing the more than 200 works from the Budapest state collections on show now until December 12 in the autumn exhibition at London’s Royal Academy.

Huge in breadth and huge in wealth, Treasures from Budapest: European Masterpieces from Leonardo to Schiele is a once-in-a-lifetime opportunity to see works like these in London. Interestingly, this outstanding exhibition was also incredibly rapidly organised after one that was to show the Liechtenstein collection this autumn fell through. Into the breach stepped Budapest — the Museum of Fine Arts, which holds the state collection of international art works in Hungary including the fabulous Esterházy collection built up between the 17th and 19th centuries by the Esterházy princes, and the Hungarian National Gallery.

With the curators feeling like kids in a candy shop, having carte blanche to select what works they will, London and Budapest have put together a show that virtually amounts to a who’s who of art history: Leonardo da Vinci, Raphael, Cranach, El Greco, Rubens, Il Guercino, Murillo, Goya, Manet, Monet, Gauguin, Picasso — and more.

And in two rooms of Old Master drawings: Dürer, Altdorfer, Carracci, Tiepolo — along with two of Leonardo’s finest drawings, as said by curator David Ekserdjian. These aggressive heads of soldiers, in red chalk and in black, were studies for a mural of the Battle of Anghiari planned for a Florentine palazzo.

Many of the works have not been loaned before. Even if you travelled to Budapest you would not see them like this, for as well as paintings and sculpture from the early Renaissance up to the 20th century, the show includes a large number of Old Master drawings, not normally displayed, thus avoiding light damage.

The exhibition also enables rare juxtapositions: the pair of paintings by Goya, for example, the female Water-carrier and male Knife-grinder (both c.1808-12). For many years thought just to be genre works, the paintings may represent Spanish resistance to occupation by the Napoleonic forces: the woman stands square, defiant-looking, bringing water to quench the troops’ thirst; the man sharpens the men’s resolve as much as their weapons.

Keeping these prized works company are some equally prized small bronzes. The Rape of Europa, attributed to Andrea Riccio is beautifully dramatic. The mounted warrior in the same room is a very rare sculpture by Leonardo, possibly used as a study for the Battle of Anghiari. With a show of this quality it is hard to isolate highlights. In the opening room alone I was spoilt for choice, struck first, as all visitors will be, by its centrepiece, a tall St Andrew Altarpiece, 1512, from a village church in what is now Slovakia, here to draw attention to the skill of early Hungarian wood carving.

An absolute gem of the Esterházy collection is the early Raphael painting known as The Esterházy Madonna. This small Virgin and Child with St John the Baptist is not only beautiful, an engaging tender portrayal of mother and wriggling infants, but jewel-like in its clarity. Originally it was not hung on a wall, as here, but kept as jewel in a case and brought out only on special occasions.

Besides seeing familiar names, it was a pleasure getting to know work by Hungarian artists. Among these was the last ever portrait of Franz Liszt painted by Mikhály von Munkácsy (1844-1900), and another of his, quite different, a rather Turner-esque landscape.