A masterpiece of the Northern Renaissance, known as the Ghent Altarpiece, has returned to its original location in Belgium after eight years of controversial restoration. The €30 million (£26 million) project will preserve and protect the Van Eyck painting, infamous for being the most stolen artwork of all time.

Jan Van Eyck (1390-1441), with help from his brother Hubert (1385-90-1426), completed the ‘Adoration of the Mystic Lamb’ for St Bavo’s Cathedral in Belgium in 1432. Over twelve imposing panels that measure 3.5 by 4.6 metres, the Van Eyck brothers depicted the Christian story of Christ’s sacrifice in striking realism.

But the oil painting had sustained a fair amount of damage over the years. It was nearly burned by rioting Calvinists, stolen by Napoleon Bonaparte (1769-1821), cut in half by Frederick William III of Prussia (1770-1840) and looted by Adolf Hitler (1889-1945) who intended to blow it up with dynamite. One of the 12 panels is still missing following the Nazi theft in 1934.

“Jan van Eyck was a genius who has been astonishing the world for more than five centuries with his innovative techniques,” commented Jan Jambon, the prime minister of Flanders. “Both the magnificent restoration and the circumstances in which the Ghent Altarpiece can now be admired are astonishing.”

Costing €2.2 million (£1.8 million), the painstaking restoration has taken place at Belgium’s Royal Institute for Cultural Heritage since 2012. The project went viral last year after conservators uncovered the original, albeit surprisingly humanoid, face of the Mystic Lamb. Even Hélène Dubois, the project’s head restorer, described the face as “cartoonish” and “a shock for everybody”.

The conserved altarpiece is now displayed in a six-metre-tall climate controlled case with bullet-proof glass. For the first time visitors can see both the elaborate front panels, as well as the more sober reverse paintings of Old Testament figures and donors. The unveiling took place in the cathedral’s Sacrament Chapel, close to the painting’s original site at the Vijd and Villa Chapels. By moving the altarpiece to a bigger space, restorers hope the sheer number of tourists that visit each year will no longer pose such a threat.

“It confronts us with human’s eternal quest for mystery,” remarked Bishop Van Hecke of St Bavo’s. “I am convinced that many people will find personal resonance here.”