The “Rex” (a king or ruler) is one of the most important themes in M.K. Čiurlionis' creative work. The artist first began to explore the existence of a ruler of the world in his early work.

The “Rex” triptych is one of the earliest variations on this theme. Here, Čiurlionis experiments with a new principle of presenting images: cinematographic close-ups and wide shots of the scene captured at the same moment.

Three hieroglyphs come into view on the plinth beneath the deity's feet. It is obvious that this is coded information, however, the inscription has not been deciphered up to date. It is thought it means “Rex” – like the name of the painting.

It is well-known that brothers Konstantinas and Povilas Čiurlionis liked to create coded alphabets. They had several of these, but no single one provides any specific insight into the meaning of this inscription. We can only guess that the answer to this mystery lies somewhere among the coded alphabets that did not survive.