In the second half of the 14th century, residential quarters in the area of the Small Minaret and to the southeast of it disappeared. This may have been a consequence of the 1361 campaign of the Golden Horde Khan Bulak-Timur. Here, a noble cemetery emerged, from which several tombs and mounds have been preserved, hiding the ruins of stone buildings. An excavation was laid on one of these mounds. It turned out to conceal the ruins of a small mausoleum, of which only the foundation and a pile of stones remained. The only burial was found to have been looted. The cemetery near the Small Minaret is traditionally called the "Khan's" cemetery. Stone tombstones remained over individual graves for a long time. The graves stretched in rows from north to south — most burials were made in boxes, over which small stone crypts were built. In the second half of the 14th century, a minaret was built here, which, unlike the Large one at the Cathedral Mosque, was called the Small Minaret, said to have been erected on the site of the burial of the "holy Bulgars." The minaret is an integral part of numerous surrounding tombs, the cemetery, and memorial mosques. Excavations showed that on the southern side of the minaret there was a narrow wall, the stones of which were completely taken by local residents. At the site of the former building, there was a pit filled with construction debris, possibly the remains of a mosque. The minaret is a massive 11-12 meter tall pillar. Its lower cubic base smoothly transitions, with the help of flat triangular chamfers, into an octagonal intermediate tier decorated with six-petaled palmettes, which connects to the round base of the tall cylindrical shaft. On the large shaft stands a second, smaller diameter shaft, around which is a circumferential gallery. The walls inside and outside are faced with carefully hewn tuff limestone blocks and partially plastered. A spiral staircase of 40 steps leads to the upper platform.

The entrance is located on the northern side. It has a semicircular top framed by a rope molding and a band of vegetal ornament. On the western side at the level of the entrance is a niche crowned with a pointed arch, decorated above with two richly ornamented slabs. It is quite possible that the niche served as a place for collecting offerings. The minaret has several windows located at different heights. The heaviness of the proportions and the treatment of forms relate the minaret to fortress towers. Probably, they also served such a function, thus approaching the type of early Azerbaijani minarets. The tent-shaped top is close to Crimean and Asia Minor minarets. The Small Minaret was repaired in 1972-74. The destroyed sub-tent part of the upper cylinder and the cornice of the gallery were restored. Found details were put back in place, the internal spiral staircase was restored, almost all the facing was repaired, and the cut-off upper corners of the octagonal tier were reconstructed.

Sources:

https://ru.wikipedia.org/wiki/Файл:Ханская_усыпальница_и_малый_минарет_в_Булгаре.jpg

http://www.bolgar.info/m_minaret.php