The first scientific description of the ruins of Khalifa Erezhep was made by A.Yu. Yakubovsky. He called it a nameless mausoleum. Based on some design features, A.Yu. Yakubovsky dated its construction in a wide range of the 12th - 14th centuries (Yakubovsky, 1930, pp. 577-578). In 1986-1989, the Research Institute of Restoration (Tashkent) conducted a comprehensive study of Khalifa Erezhep, which included architectural measurements of the structure, archaeological excavations inside the monument and around it.

As a result of the research, the design features of the monument were revealed; two stages of its existence were distinguished; traces of structures inside the monument were cleared, including the remains of a tombstone (?); significant material was found on the design of the facade, which made it possible to make options for reconstructing the appearance of Khalifa Erezhep; structures that were attached to the facade were excavated.

a tromp with a fragment of the dome. From the photo album of A.S. Melkov. 1939"

It should be noted that the participants of the research group did not come to a consensus regarding the dating of the Khalifa Erezhep . In this regard, candidate of architecture K. Kryukov - the author of the review of the final report of the comprehensive study - proposed the following wording: "... the mausoleum of Khalifa Rajab could not have been built earlier than the first half of the 12th century and no later than the beginning of the 13th century. Doubts are raised by the too early dating (11th century) (proposed by the authors of the comprehensive study Report, p. 27) and too late (beginning of the 14th century)." Several years later, one of the participants of the research group G. Khozhaniyazov spoke about the dating of the construction of the Khalifa Erezhep and its functional purpose. He wrote that the monument was built in the 11th - early 12th centuries.

In his opinion, initially, it functioned as a mosque-madrasah. In the first half of the 14th century. (1344-1345) burials were made in the building, and it began to function as a mausoleum.

Researches

In 2023-2024, with financial support of the US Ambassador's Fund for Cultural Preservation (AFCP), a complex of studies (archival, archaeological, architectural) was conducted to have a better insight into the monument’s history.

The monument is remains of a monumental architectural structure. The southwestern (facade) wall and the dome have not survived. Initially, it was a separate building, square in plan (12.25 x 12.35 m), having a cubic volume (a quadrangle) covered by a dome. The transition to the octagon, on which the dome was installed , is made in the form of a system of arched trompes placed at the corners of the quadrangle. The question of the presence of an internal dome remains open. There is no data on the external dome’s shape – conical or classical (oval).

As a result of the research, it was possible to determine that the building was built on a site cut into a hill: the Eastern Hill is an elevation consisting of limestone-shell rock. The prepared site is leveled with a layer of river sand (8-10 cm thick).

The peculiarity of the Khalifa Erezhep is the combination of burnt and adobe brick structures. The foundation of the building is made of burnt bricks. The role of the foundation is performed by the masonry of burnt bricks (four rows), which is wider than the thickness of the wall. The masonry of burnt bricks at a height of 1.05 m is covered by a layer of reeds ("berdan"), which served as waterproofing. Three rows of burnt bricks are laid on top of the reed layer. Above this follows the masonry of adobe bricks at a height of 6.12 m from the base of the walls.

At the same time, the entire facade wall (judging by the preserved eastern part) was made of burnt bricks. In addition, the structures for the transition from the base quadrangle to the dome (trompe) and the dome were also made of burnt bricks. The monument uses arched trumpet slabs made of larger burnt bricks (40 x 40 x 5-6 cm). In the corners of the trumpet slabs, there are “nests” with the remains of wooden beams, which served to strengthen the trumpet slabs.

drawing of the upper part of the collapsed portal - according to archaeological data

Excavations

Archaeological excavations in 1986-1989 made it possible to establish the existence of two construction stages of the functioning of the Khalifa Erezhep: 1/construction; 2/repair. In addition, a complex of structures attached to the facade during the period of its functioning was excavated near the facade wall of the monument

In 1986-1989, a layer of façade rubble was cleared in front of the southwestern (façade) wall. Excavations showed that the façade had a "shirt" of facing bricks laid in a bond with the masonry of the wall body. Probably, the structure did not have a special dedicated portal. Based on the materials obtained, previous researchers proposed two versions of the façade reconstruction, the main difference between which was the shape of the dome. In the first version - conical; in the second - classical (oval). Without arguments to justify what kind of dome the Khalifa Erezhep had, the most significant for us is the differences in the façade decor. In both cases, the façade was divided by three perspective arches. In the central arch, there was a passage into the structure.

The planes of the two pilasters flanking the central arch, as well as the strip under the cornice were decorated with geometric decor of carved polished bricks. The tympanums above the arches are decorated with a more complex geometric girih made of polished figured bricks. In the first version of the reconstruction, the composition of the facade was completed by a U- shaped frieze of terracotta bricks with a carved inscription in Arabic script.

The second version of the reconstruction includes a rectangular space ( ktaba ) located above the tympanums. The ktaba was made of glazed terracotta slabs covered with monochrome turquoise glaze (fragments of slabs 44 x 28 cm) with carved epigraphy. The U-shaped frieze with epigraphy made of polished carved bricks was preserved.

The remains of the entrance portal (peshtaka)

A preserved fragment of the eastern tromp

An analysis of fragments of decoration with epigraphy allows us to draw certain conclusions about the dating and purpose of the monument.

Summarizing the results of previous studies and analyses of the materials collected within the framework of the US Ambassador's grant project, it is possible to identify several stages in the history of the existence of Khalifa Yerezhep and propose options for the purpose of the monument.

Construction. As part of the AFCP project, analyses of the remains of wooden beams in the trompe l'oeil construction were carried out, which yielded a date of the second half of the 12th - first half of the 13th centuries (see Link to analyses). Given the political situation in the region, the construction can be dated within a narrower range - the end of the 12th - beginning of the 13th centuries.

Despite the suggestion of G. Khozhaniyazov, who believed that Khalifa Erezhep was originally a mosque/khanaqah, there is no data to support this. Therefore, the question of what the original purpose of the monument was remains open.

Repair work

Repair work. Dated to the first half of the 14th century. Gravestones appeared in the building , and it began to be used as a mausoleum, where, according to epigraph analysis, a significant representative of the Sufi community could have been buried.

Construction of a complex of rooms near the façade wall / 15th century. Functions as a mausoleum

Collapse of the facade wall and dome / XVII – XVIII centuries. The transformation of the Khalifa Erezhep into ruins, which began to be used as a cemetery.