You are here:Home/Resources/ Byzantine Seals/ Introduction to Byzantine Seals and the Online Catalogue

Introduction to Byzantine Seals and the Online Catalogue

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

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).

Using the Online Catalogue

How to Search

Begin searching by selecting “Search the Catalogue” on the left-hand menu. Facets allow you either to perform a general text search, or to narrow down the options by date, location, title, or office. At the top left, select “More Filters” to search by obverse or reverse iconography, type of seal (metrical or iconographic), or language.

Please note, if you would like to search a specific phrase in the general search text box, put the search terms in quotation marks.

My Seals

To save a seal for later consultation click the “Add to My Seals” button, located above the accession number. Once you have saved a seal the "My Seals" link will appear on the bottom of the left-hand navigation menu.

Please note, your list of seals will save in the browser for the length of your session, so be sure to print or email the list before leaving the catalogue.

My Seals List and Comparison View

Clicking on the my seals list opens the list of saved seals. Once in the list view any two seals can be selected for comparison. Click the box next to each seal then the “Compare” button at the bottom of the list. This will open the comparison view where you will be able to see a shortened version of the entries for the two seals side by side. To access the full entry for one of seals click on the accession number.