Peter of Diokleia or Petar was an archon

Archon

Archon is a Greek word that means "ruler" or "lord", frequently used as the title of a specific public office. It is the masculine present participle of the verb stem ἀρχ-, meaning "to rule", derived from the same root as monarch, hierarchy, and anarchy.- Ancient Greece :In ancient Greece the...

of Duklja

Duklja

Doclea or Duklja was a medieval state with hereditary lands roughly encompassing the territories of present-day southeastern Montenegro, from Kotor on the west to the river Bojana on the east and to the sources of Zeta and Morača rivers on the north....

 in the 10th or 11th century. The only information on him is from a seal found in the 19th century, which is decorated on the observe with a bust of the Virgin Mary holding a medallion of Christ

Christ

Christ is the English term for the Greek meaning "the anointed one". It is a translation of the Hebrew , usually transliterated into English as Messiah or Mashiach...

 and flanked by two cruciform

Cruciform

Cruciform means having the shape of a cross or Christian cross.- Cruciform architectural plan :This is a common description of Christian churches. In Early Christian, Byzantine and other Eastern Orthodox forms of church architecture this is more likely to mean a tetraconch plan, a Greek cross,...

 invocative monogram

Monogram

A monogram is a motif made by overlapping or combining two or more letters or other graphemes to form one symbol. Monograms are often made by combining the initials of an individual or a company, used as recognizable symbols or logos. A series of uncombined initials is properly referred to as a...

s. The text is in Greek letters, saying ΠΕΤΡ[Ο]Υ ΑΡΧΟΝΤΟΣ ΔΙΟΚΛ[Ε]ΙΑ[Σ] ΑΜΗΝ (Petr[o]u, Archontos Diokl[e]ias, Amen), i.e. "[Seal] of Peter, archon of Duklja, Amen

Amen

The word amen is a declaration of affirmation found in the Hebrew Bible and New Testament. Its use in Judaism dates back to its earliest texts. It has been generally adopted in Christian worship as a concluding word for prayers and hymns. In Islam, it is the standard ending to Dua and the...

". The seal shows that although Duklja underwent turmoil in the 9th century, the region still continued under Byzantine

Byzantine Empire

The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...

 rule or at least cultural influence.

The stamp was kept in the Medal cabinet of Berlin

Berlin

Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

 and before 1884 it was in a decayed condition. Illustration based on the original by Dardel, was first published in 1884 by Gustave Schlumberger

Gustave Schlumberger

Léon Gustave Schlumberger was a French historian and numismatist who specialised in the era of the crusades and the Byzantine Empire. His is still considered the principal work on the coinage of the crusades....

.

The history of Duklja until the 10th century is little known. A list of mythological rulers of this time exist in the dubious Chronicle of the Priest of Duklja

Chronicle of the Priest of Duklja

The Chronicle of the Priest of Duklja is a medieval chronicle originally written by a Catholic monk of the Cistercian order by the name of Roger for the Croatian Ban Paul Šubić because an order form by Ban Šubić and a quote of Catholic monk have been discovered...

 compiled in the 13th century or even the 16th and 17th centuries. In this chronicle, the father of Prince Jovan Vladimir

Jovan Vladimir

Jovan Vladimir or John Vladimir was ruler of Duklja, the most powerful Serbian principality of the time, from around 1000 to 1016. He ruled during the protracted war between the Byzantine Empire and the First Bulgarian Empire...

 (ruled ca. 1000 – 1016) is named Petrislav, possibly meaning that Peter and Petrislav are the same.