Šimuna) is a rectangular cedarwood sarcophagus in the shape of a chasse, overlaid with silver and silver-gilt plaques, said to hold the relics of St Simon the God-receiver; it is located over the main altar in the Church of Saint Simeon in Zadar, Croatia.

The chest, considered a masterpiece of medieval art and also a unique monument of the goldsmith's craft of the age, is one of the most interesting works in gold in Europe now under the protection of UNESCO.

The top of the chest containing the mummified body of the silver-crowned bearded saint enclosed behind a sheet of transparent glass is elevated above the main altar and displayed to the public, as well as its interior full of precious gifts given by Elizabeth of Bosnia, every year on 8 October, at 8:30 a.m.[3][4][5][6][n 1] Eastern Roman emperors who were seated in Constantinople in the sixth century were not only expanding their collection of valuable works of art, but also relics of saints in order to be able to stand side by side with Rome's.

Shortly after that, gossips about this story reported by the monks and miracles performed in the name of the saint began to spread around the region inciting to the locals to refuse to let his body leave Zadar.

[11] On 16 May 1632 they were transferred once more amid public rejoicing to a church consecrated to St. Stephen, the Martyr, and which subsequently came to be known as the Sanctuary of Saint Simeon the Righteous, the prophet of the Nunc Dimittis.

When Elizabeth finally left the church she promised to honour the saint by presenting the church with a gift ornated in gold that she later came to commission to the Milanese goldsmith Francesco di Antonio da Sesto (Francis of Milan), who was asked to create a paper model with drawings of all the details to be discussed and approved by the queen's representatives so that their legibility and presentation might be in accordance with the royal expectations and deep interest in the making of such precious shrine.

[5] The front side of the lid is dominated by the carved reclining figure of the saint dressed in a gown and cloak richly ornamented with plant motifs made by punching fastened on his breast by a clasp.

[16] Covered inside and outside with a thin lamina of 240 kg of pure silver and also a considerable quantity of gold, it shows intricate details carved on the cedar wood used to give shape to the chest.

[14][17] The front part of the chest displays enhanced relief compositions depicting scenes from the saint's early years as a preacher, death and ascension into heaven on the back of a virgin,[15] as well as biblical and historical events of his time.

"[14] Known in medieval Latin hexameters, the translation of the inscription reads as follows: "Simeon the Righteous, holding Jesus, born of a virgin, in his arms, rests in peace in this chest, commissioned by the Queen of Hungary, mighty, glorious and majestic Elizabeth the Younger, in the year 1380.