Although the studies on construction materials and construction techniques have increased in recent architectural history research, they have not yet reached a developed level. The plan and space arrangements of historical buildings provide information about the level of architectural development of the period in which they were built. The ornamentation programs in the buildings show the reflections of the understanding of aesthetics and beauty. The construction and decoration materials used in the structures provide information about the geography and geoscience of the region. The simplicity or diversity of the use of construction and decoration materials in historical buildings reflects the architectural understanding of the region where the building was constructed. Another notable feature is the use of spolia. Due to the expedient procurement and straightforward applicability of the spolia material, it is encountered in every age. The high number and variety of spolia usage in Anatolia is worthy of particular interest.

The choice and application of spolia materials during the Anatolian Seljuk Era and the Ottoman Empire reveal remarkable causes and consequences. It is seen that the use of spolia materials was abundant in the architecture of the Seljuk period. The fact that the Seljuks carried out many construction activities in the short time they spent in Anatolia must have caused them to prefer construction and decoration materials in buildings belonging to old and different societies, as well as the production of new construction materials. In the Middle Ages, traces of architectural pieces from the Hellenistic, Roman and Byzantine periods can be seen on the works of the Turkish-Islamic period, especially in the monuments in the Central and Western Anatolia Region. In Ottoman architecture, the use of spolia architectural pieces, especially in the Classical period, in harmony with the original material makes it difficult to immediately recognize the spolia material. When the architecture of Anatolian Seljuks and II. Principalities period is examined, spolia materials were used in columns, column bases and capitals, masonry, arches, balustrade panels, lintels and architraves, and were also used as an ornamental material. The reason why spolia is frequently preferred in centers such as Konya and nearby cities, the Western Anatolia Region, Bursa, Istanbul and Diyarbakır is that some buildings have become unusable and have turned into ready-made material warehouses. However, since Christian communities continue their lives and use their buildings in many settlements of the Eastern Anatolia Region, the use of spolia materials in Turkish-Islamic monuments is rare in this region.

The Gevaş Izzettin Shir Mosque, located in the Gevaş district of Van province and although its first construction date is controversial, researchers generally accept that it was built in the 14th century, reflecting the characteristics of the Medieval Anatolian Turkish-Islamic mosque architecture with its dome in front of the mihrab and the transverse aisles behind it. The tomb inscription dated 1197, located to the east of the mosque mihrab, reveals that the architecture in the area began much earlier. A madrasah unit was added to the northern façade of the place of worship in 1594-1595, and a minaret was added to the western façade recently. It is understood from the traces on the walls of the work in the form of a complex and the restoration reports that it has undergone a restoration process spanning many years. However, these renovation works have also brought with them some questions. 

It is obvious that the tomb monument inscription on the east side of the area in front of the mihrab and some stones found in various parts of the building belong to another building. A total of 11 qualified spolia materials were found in this structure. It is thought that 8 of these belong to a tomb monument (gunbad) and two of them are tombstones. It is not clear whether one piece is an architectural piece or a tombstone. In addition, a large number of undecorated building stones, thought to be spolia, were used on the facades of the Izzettin Shir Mosque. Introducing the spolia stones that differ in structure gives ideas about which type of structure they belong to and from where they would have been brought.

The inscription on the right side of the mihrab (Harim Stone No. 1) belongs to a grave monument (hazire) and the name of Shah Sarimuddin, who died in January 1197, is written on it. Harim stone no. 2 is located in the corner of the arch on the north nave and is a 5-armed medallion decoration on limestone. Stone no.1 on the south façade of the mosque has the same decorative composition as stone no.2 on the harim. Stones no.2 and no.3 on the south façade and stone 1 on the east façade have the same formal and decorative features.

These stones, which are thought to be border arrangements, have a round-surface carving technique, a decoration similar to the “zencirek” motif, continued with broken and straight lines. The stone no.2 on the eastern façade of the mosque is a horizontal rectangle and there are three ornamental panels on it. Since these decorations were destroyed, their nature could not be understood. Composition panels were probably created from similar decorations. Madrasah student cell stone no.1 is a gravestone, but it has not survived to the present day because it was removed during repairs. There is a 10-pointed star motif in the center of stone no.1 on the north façade of the madrasah. Stone no.1 on the east façade of the madrasah is also a piece of a tombstone. There is a burning candle motif in the frame at the center of the stone. The candle pattern is filled with reverse palmette, knot and rumi motifs on both sides. In addition, there are white-textured limestone stones on a large surface on the upper rows of the eastern façade of the mosque. The fact that these stones are different from the other stone textures in the building shows that these undecorated stones were taken from another building.

The spolia materials in Izzettin Shir Mosque and Madrasah should be divided into two groups: tomb monument architectural pieces and tombstones. It is thought that the majority of the decorated architectural pieces and facing stones belong to a tomb. The strongest evidence in this determination is that there is a grave monument that is meant by the word “hazire” in the inscription inside the harim. The other second evidence is the border decorations defined as the “zencirek” motif seen on the facades of this building, when we examine the tombs of the Seljuk Age in Anatolia, geometric border arrangements in the form of knitting and interlocking were frequently used in the transition section between the base of the buildings and the body. Another evidence that the stones belonging to the tomb were used is that the stones of harim 2, mosque south façade 1 and madrasah north façade 1 are similar to the use of medallions in the window and entrance openings in the tomb monuments. Since the stones of Harim 2 and the south façade of the mosque number 1 have the same symmetry, it is assumed that these stones were used as repeated decorations in the decoration program of the tomb where they were spolia. Or it can be thought that these stones were used in the arch spandrels of the entrance opening of the tomb. It is assumed that the stones numbered 1 of the madrasah student cell and 1 of the eastern façade of the madrasah are not architectural pieces but were originally used as gravestones.

Van Province and its surroundings are located in the first-degree earthquake zone. Many monuments have been damaged or destroyed in the region which has witnessed devastating earthquakes throughout history. Since the tomb to which the spolia stones we examined within the scope of the study belonged was destroyed and became unusable, probably as a result of an earthquake, they were not used in the reconstruction of the tomb. Instead, it is thought that it was used in the repair of Gevaş Izzettin Shir Mosque as a more practical method. In addition, the placement of these spolia stones without regard to aesthetics and symmetry also indicates a local repair. 

Based on the evidence, the word “hazîre” in the inscription on the wall to the left of the mihrab was used not as a grave-burial area (cemetery) but in a context that would refer to a type of structure / grave monument in the sense of “mausoleum - tomb”. Thus, it is understood that this inscription does not belong to the mosque but is the inscription of the tomb where a person named Shah Sarimuddin was buried during the Ahlatshahs period. It is determined that the medallion decorations in the harim area, on the south façade and the north façade of the madrasah, the border decorations on the east façade of the harim and the white-toned limestone stones in the upper row are also stones belonging to this tomb due to their formal and decorative nature. The tombstone with a candle motif on the east wall of the madrasah and the tombstone used as a scarf stone in the student cell are also used in the building, and it is thought that these are the tombstones around the tomb we know of, or the stones brought from the nearby historical Turkish cemetery. In addition, the intense use of this spolia material on the eastern façade of the mosque is the strongest evidence that the tomb dated 1197 was located in this direction. In fact, this shows that Izzettin Shir Mosque may have been built in the 12th century before the 14th century and that a tomb was built near the mosque. The structures were probably damaged and destroyed by the effects of devastating earthquakes. While the mosque was being repaired, the inscriptions, architectural pieces and plastic decorations belonging to the tomb were used to raise the mosque. Thus, the existence of the earliest Seljuk Era tomb in the Lake Van Basin and in Gevaş was identified from the traces on the walls of the mosque built during the Seljuk period and the madrasah added during the Ottoman period and was brought to the history of architecture. As a result, and as indicated in Table 1, the spolia from the Izzettin Shir Mosque belong to the tomb dated 1197. However, the tombstones used in the madrasah are strongly dated to the 14th century.