The Prince of the Lilies, or the Lily Prince or Priest-King Fresco, is a celebrated Minoan painting excavated in pieces from the palace of Knossos, capital of the Bronze Age Minoan civilization on the Greek island of Crete. The mostly reconstructed original is now in the Heraklion Archaeological Museum (AMH), with a replica version at the palace which includes flowers in the background.

Though often called a fresco, the figure (not including the flat background) is one of the smaller group of "relief frescos" or "painted stuccos", as the original parts of the image are built up in plaster to a low relief before being painted. It is dated to "Late Minoan IA" by Sinclair Hood, circa 1550 BC, in the Neopalatial ("new palace") period between 1750 and 1500 BC). Maria Shaw says that estimated datings (in 2004) ranged between MM IIIB and LM IB, giving a maximum date range from c. 1650 to c. 1400 BC, "and occasionally later".

Only a few pieces of the original image were excavated; it was probably removed from its wall deliberately during rebuilding or renovating the palace. There have been a number of different suggestions from archaeologists as to the appearance of the original image, many very different from the grand male figure reconstructed a century ago. These go back to the original excavation under Sir Arthur Evans in 1901, as he first thought the fragments belonged to at least two figures, a possibility that remains under discussion. It is now generally agreed that Evans' reconstruction was considerably over-confident. The uncertainty surrounding the fragments may be summarized by the title of a paper published in 2004: "The Priest-King Fresco from Knossos: Man, Woman, Priest, King, or Someone Else?", though in fact the paper tends to back more of Evans' conclusions than some subsequent scholars do.

The fragments making up the reconstruction at the AMH are, as is usual with these displayed pieces, embedded in plaster of Paris on a backing, and framed. There are a total of nine fragments used:

The reconstruction of the so-called "Priest-king" from Knossos has always been uncertain. When the fragments were excavated under Arthur Evans (not by him personally) in 1901, his first thought was that they belonged to different personages and "the torso may suggest a boxer".

Anatomical observation of this torso shows a contracted powerful musculature and the left disappeared arm was surely in ascendant position because the pectoral muscle is raised. These observations allow us to conclude the torso was one of a boxer resembling the many athletic representations engraved on the Boxer Vase from Hagia Triada. The lily crown belonged to another personage, perhaps a priestess (like on Hagia Triada sarcophagus). The painted reliefs of two athletes boxing in the palace of Knossos were surely the model of the "boxing children" fresco in Akrotiri at Thera.

Evans later changed his mind, and the reconstruction reflects his later idea of the figure as a "Priest-King"; he used the image on the cover of all volumes of his main publication on the Knossos excavations, despite the cost of gold-embossing the crown. Evans' change of mind was perhaps largely because he had decided that the original painted wall with the fresco was part of a processional corridor in the palace, and the figure one of a group of others shown in procession, via another corridor, towards the Central Court of the palace, always thought to be the place where bull-leaping took place. In the reconstruction, the rope in the invented hand at right was, Evans thought, leading a sphinx or a griffin; a bull being led to a ceremony or sacrifice might be another possibility, but in fact there is no evidence the missing arm held a rope at all.

The fresco griffins from the "Throne Room" wear plumed crowns comparable to the "Priest-King", and if his crown in fact come from another figure, that would be a possibility. In the view of Nanno Marinatos, in Minoan art "the plumed crown" is only worn by deities, griffins and the queen, who is, by definition, also the chief priestess.