Skip to Content

Introduction to Byzantine Seals and the Online Catalogue

Types of seals, critical signs, glossary, and instructions on how to search

For centuries the Byzantines, from humble monks and laymen to highly placed grandees and emperors, used lead seals to “lock” official and private correspondence and to validate or authenticate documents. The details contained on the thousands of seals preserved shed light on many aspects of the Byzantine world, principally the structure of its civil, military, and ecclesiastical administrations, the careers and locations of its officials, and the responses to the ever-changing fortunes of the empire over its millennial existence.

The inscriptions on the seals echo, as their images reflect, the beliefs and perspectives of people who but for the survival of their seals would be lost to history. The seals often provide the key evidence needed to outline a career, to chart the rise and decline of a family, or to confirm the presence of an individual at a given place or time. The invocations or prayers in which so many inscriptions are phrased combine with a remarkable range of iconography express personal piety in a devoutly religious society, one in which all people, from the sovereign to the lowliest subject, entrusted their earthly welfare and hopes for salvation to a vividly conceived array of tutelary or intercessory powers. And although the inscriptions and images on seals tend to conform to standard patterns, unique compositions in the form of short poems or singular examples of images or scenes stand out as attempts to make an individual’s seal truly distinctive and memorable.

Byzantine Seals and Sigillography

Seals served two main purposes: to authenticate and to secure.

Lead seals began as blanks, or round discs, which were cast, usually in standard sizes, in slate moulds. Each blank had a hollow channel running through the middle, through which string was threaded when a letter was tied or when a seal was attached to the bottom of a document. The design of the seal, which was carved incuse on a pair of dies, was impressed on the seal by striking the blank with the boulloterion, a plier-like instrument that held the two dies. The act of striking also collapsed the channel around the string.

Seals can be distinguished according to a number of different criteria, including material, inscription and image, and issuer.


“Seal” in Byzantine sigillography refers to both the instrument making the impression and the impression itself (the “sealing”). Four materials were used:

  • Gold (chrysobull)—the golden seal was reserved for the emperor, and is of varying weights depending on the importance of the recipient.
  • Silver (argyrobull)—a silver seal was used by the despots of Epiros and the Peloponnese.
  • Wax—wax seals do not survive in great numbers, but the implements which created them, such as sealing rings, cone seals, and bi-valves, have survived in greater numbers.
  • Lead—the majority of the surviving seals from Byzantium are made from lead.

Inscription and Image

In addition to material, the seals can be distinguished further according to the type and arrangements of the inscription and design. Seals could include one or more of the following:

  • Inscription—the inscription on the majority of seals identifies the seal owner, and could include his or her name, rank, office, and area of authority. Many inscriptions begin with an invocation for the help of some holy figure—typically the Theotokos or God, but also Christ or the Trinity—followed by the owner’s information in the dative case (rarely the genitive). Typically, inscriptions are written out over several lines on one or both sides (bilateral inscriptions), but they may also be found around the circumference of the seal. In the eighth and ninth centuries especially, the invocation is presented as a cruciform monogram, with “your servant” (τῷ σῷ δούλῳ or τῷ δούλῳ σοῦ) typically included in the four quadrants. Metrical inscriptions, usually of twelve or, less frequently, fifteen syllables, are particularly popular in the eleventh and twelfth centuries. Many metrical inscriptions are also anonymous.
  • Image—two types of images were employed on seals: religious and secular. Religious images include images of the Virgin and Christ (usually accompanied by sigla, or abbreviated form of the name), various saints, as well as the cross and Old and New Testament narrative scenes. Secular images include portraits of the emperor and real or mythical animals. This catalogue identifies those seals with images on both obverse and reverse as “iconographic.”
  • Monogram—a monogram can be either block or cruciform; some seals, especially from the late sixth and early seventh centuries, include both types. The letters included in the monograms can spell out an invocation or the owner's name, dignity, or office, or some combination of these. For cruciform monograms, additional information, such as name or office, is written in the four quadrants.

Owners and Institutions

Finally, seals can be grouped according to their owners, whether individuals or institutions:

  • Imperial—the seals of the emperors and their immediate families are a category unto themselves. In many ways, they are often more similar to coins than other seals in terms of iconography and inscription. More information can be found in “God’s Regents on Earth: A Thousand Years of Byzantine Imperial Seals.”
  • Patriarchal—similar in many respects to the imperial seals, these seals followed a set pattern with respect to their design, iconography, and titulature, which remained remarkably consistent over the life of the empire.
  • Official—seals belonging to individuals active one or more parts of the imperial administration, including military, civil, ecclesiastical, financial, and judicial. These seals are distinguished by the inclusion of an office and, where appropriate, an area or region of authority.
  • Private—seals that can include the owner’s name and rank or dignity (ἀξία διὰ βραβείου), a lifelong honorific title. These seals are distinguished by the exclusion of an office. This does not mean, however, that the seal owner did not hold an office at the time the seal was used, but rather that the seal does not provide direct evidence of the owner’s official capacity.
  • Monastic—seals both of individual monks and abbots exist in great number.
  • Institutional—seals that belonged, broadly, to local or state institutions. These include civil, ecclesiastical, fiscal, and local bodies, as well as individual monasteries.

Cataloguing Conventions

Critical Signs

ẠḄ letters of uncertain reading

.... illegible letters (exact number)

. . . missing letters (unknown number)

(αβ) abbreviation

[αβ] reconstruction of lost or illegible letters

<αβ> restoration of letters either omitted or misleadingly written by the engraver

{αβ} superfluous letters that appear on the seal


With some exceptions, this catalogue dates seals by century; for example, tenth century represents the period from 900 to 1000, and tenth/eleventh century the period from 950 to 1050. Precise dating is possible in a few circumstances, usually based either on indictional dates on the seals themselves (on seals of kommerkiarioi) or on the tenures of known individuals in office (e.g., emperors or patriarchs).