The subject of this publication is three seals, each raising interesting questions. During the archaeological explorations of the ancient city of Serdica (now Sofia) conducted in the past ten years, 48 lead seals from the 4th – 7th A.D. period have been discovered. The scientific novelty of the discovered bullae are little-known specimens, or not described until now in the specialized literature. The description of all of the seals is given. The first one relates to John, excavated at the ‘Metro station 8 II’. The print is perfectly preserved with a very strong relief of the images of the Virgin with Child between two cypresses is relatively rare in combination with various reverses unpublished till now. It dates back to the 6th A.D. The second Byzantuim seal excavated at ‘Vesletz’ 13. (the territory of ancient Serdica) and there are there are no analogues.During the early Byzantine Empire, only the first or baptismal name was used on seals. The parents had a large choice of names: Latin names or their Hellenized versions were used in the eastern part of the empire, traditional Greek names with regional traditions were widely used, also names of Christian saints appeared, which gradually became very popular. As a result, every twelfth child was baptized with the name John, and as a result there are a large number of bulls named John , and some have the same name on both sides, which is usually explained by the kinship between the two persons . In order to identify the person, in some cases his position or title is added, but even this information is not enough to identify the owner of the seal, known to us from documentary or epigraphic sources.Another seal from ‘Vesletz’ 13 has an image of the Mother of God that is of the earliest type presented on the seals. There are different variants of the described monogram, there is no identical to the one on the seal from Serdica, also difference being in the position of the letter Р. In Bulgaria, only 3 copies of persons with the title patricius (VI–VII c.) are described, two with a block monogram and one with an inscription. In the seals discussed above, the names and the title of the owner are given in monogram form. Generally there are two types of monograms: block and cruciform. It is accepted that the first type appeared not earlier than the fifth century, when on the coins the name was also written in this way. The letters are located at the ends of the cross or at the intersection of its shoulders. This shape, as well as the angles formed, allows a large number of letters to be used. Conclusions. Usually, seals like the ones presented above dated to the period 6th-7th A.D. An important circumstance for the bullae from Serdica is that they were found during archeological excavations, in stratified sites and in layers with dated numismatic material, in which the coins of Emperor Justinian I (527–565) and Tiberius Constantine (578-582) predominate. This is an important indication, which makes it possible to specify the dating of the bulls no later than 2½ of the 6th A.D.