The room devoted to the burials of   Beys who actually reigned is the most remarkable and the largest. It is notable for its layout and decoration, which takes after the Sultan Ahmed Mosque in Istanbul. It has a square plan, with sides measuring 15 metres, and is topped by a central dome covered on the outside with green glazed tiles. Four large cruciform pillars support a large, slightly bulbous central dome which is shouldered by four half-domes as counter-domes on the sides and four cupolas at the corners.  The upper parts of the hall are completely covered with stucco with geometric plant motifs, such as cypresses and vases, as well as epigraphic friezes derived from Ottoman oriental traditions, interspersed with polychrome claustrums covered with tainted glass.

The white of the domes contrasts with the side walls of the hall and its pillars, all of which are covered with imported marble of different colors (yellow, brick-red, black, white). The panels are decorated with carved vases from which intertwined leafy branches spring, topped by stars and crescents, held by two birds, all of which are made in marble marquetry by the most skilful Italian sculptors.

The largest burial hall is devoted to the tombs of the thirteen Husaynite beys who actually reigned. Not included is Muhammad al-Hadi Bey (1902-1906), who was interred in an adjacent room. It also contains the tombs of three princes of the Husseinite House and three children, in addition to a carved and painted wooden catafalque over the tomb of the holy man Sidi Hasan al-Sharif, who died in 1191 (1777H). All tombs are dug into the soil and are covered with marble chests abundantly decorated with geometrical and plant motifs in bas-reliefs, above which stand prisms engraved with epitaphs in thuluth Arabic script, bearing the name of the deceased, the date of his death and verses from the Qur'an, and surmounted by a headpiece, which indicates the male sex of the deceased. All the tombs are draped with velvet fabric embroidered with silver and gold threads. Next to them are silk banners embroidered with verses from the Qur'an and verses from the Burdah (a 13th century ode of eulogy for the Prophet Muhammad). Opposite, stands the hall of the Husseinite House princesses' graves. It is a rectangle hall (10 m x 5.30 m), preceded by an entrance topped by a prominent carved marble frame and flanked by two windows. It is covered by a large dome, resting on four arches, the drum of which is pierced by polychrome glass skylights. Its interior walls are lined with polychrome ceramic tiles with a metallic sheen, some of which were imported from Italy, while others were made locally (by the potters of the Qallaline workshops in medina of Tunis. The higher parts and the central dome are decorated with extremely fine geometric, floral and epigraphic motifs in naqsh hdida (plaster carving) of Ottoman influence. This room is home to fourteen tombs devoted to the spouses, princesses and concubines of the Husseinite House, including Princess Jannat, the daughter of Ali Bey, the initiator of the Tourbah, who was the first woman to be buried threin in 1777 (AH 1191), along with her sisters Turkiya, who died in 1778 (AH 1192), and Aisha, who died in 1782 (AH 1196). All their tombs were carved in ornate white marble and epitaphs were erected above them with funerary inscriptions in kufic script.

The two halls devoted to the beys who actually reigned (beys of the throne) and the princesses, together with the open-air patio, make up the first nucleus of the mausoleum built by Ali Bey, the initiator of the tourbah in the 1870s.

The abovementioned Hall of the Princesses opens directly onto a third 7x 7 m room, which is square in shape and very similar to the above room in terms of layout and decor. Covered by a central dome, this hall was added on during the reign of Mahmud Bey (1814-24) and was in turn devoted to the harem of the Husaynite House. It contains 16 tombs, including the grave of Princess Fatima Bayah, the granddaughter of Osman Dey and wife of Hussein Bey II (1824-35), who died in 1827 (AH 1242).  It also shelters the tombs of concubines and servants of the Husseinite House.

The Tourbet el-bey has undergone successive extensions and additions in response to the growing number of tombs. Thus, a fourth room was added during the reign of Ahmed Pasha Bey (1837-1855), on the southern side of the central patio, designed on the same model as the preceding rooms. It contains the remains of twenty Husseinite princesses, including the mother of Marshal Ahmed Pasha Bey (1835-55) 'Lalla Jannat', who was laid to rest here in 1846 (AH 1263). The fifth room is located on the south-eastern side of the turbah and was constructed at the beginning of the reign of Muhammad al-Sadiq Bey (1859-1882). It is notable for its elliptical dome that is devoid of decoration. It shelters fifteen tombs, the most ancient of which is that of Khadija, daughter of Ismail Kahiya (Georgian Mamlouk of Hammouda Pasha Bey), who passed away in 1861 (1278 A.H.). The grave of Princess Zuleikha Beyah, daughter of Hussein Bey II and wife of Ali Pasha Bey (1882-1902), who died in 1883, is also to be found in this room.

The rest of the rooms were added from the 1860s onwards around the second secondary courtyard of the tourbah, which contains the tombs of a number of ministers and mamluks, including that of Grand Vizier Mustapha Khaznadar. The sixth room (measuring 17.80 m x 4.60 m) was built on the southern side. Its walls are lined with polychrome ceramic tiles and it is topped by an oval dome decorated with carved plaster.

This hall was expanded to the south during the reign of Muhammad Al-Nasir Bey (1906-1922), specifically in 1918, when another hall was added at the detriment of two adjacent shops and a storeroom, the size of which was 62 square meters. These properties were acquired by way of compensation under the auspices of the Awqaf Association. This room has the highest number of tombs (28 in total), among which are those of the princes of the Husaynite House and the heir crown princes (beys lamhal), the oldest of which is that of Muhammad Al-Ma'moun Bey, who died in 1861 (AH 1278). It also houses the graves of some Grand Viziers, such as Grand Vizier Muhammad Al-Aziz Bou Attour (1906) and Grand Vizier Muhammad al-Jallouli (1908). The seventh hall is located on the south-eastern side of the secondary courtyard. It is a rectangular hall (12.25 m x 7.25 m) with polychrome ceramic tiles on the walls and a huge oval dome on top. It was added during the reign of Mohamed al-Sadoq bey, who had devoted it to the women of the Husaynite House. His sister, Princess Kabboura, who died in 1868 (1285H), was laid to rest therein. It also houses the tomb of the reigning Bey Muhammad Al-Hadi Bey, who died on 12 May 1906. He was not buried in the hall of the reigning beys, but in a separate wing alongside the tombs of his three daughters: Traki, Zubaydah, Aisha, as well as three Husseinite princesses. This wing is separated from the rest of the tombs by an openwork painted wooden screen, adorned with the coat of arms of the Husaynite dynasty, made by 'Umar bin Mahmud al-'Ajul in 1906 (AH 1324). The rest of the twelve tombs are distributed in an orderly fashion throughout the room. It also houses the tomb of the reigning Bey Muhammad Al-Hadi Bey, who died on May 12th, 1906. He was not buried in the hall of the reigning beys, but in a separate wing alongside the tombs of his three daughters: Traki, Zubaydah, Aisha, as well as three Husseinite princesses. This wing is separated from the rest of the tombs by an openwork painted wooden screen with the coat of arms of the Husaynite dynasty, made by 'Umar bin Mahmud al-'Ajul in 1906 (1324 AH). The rest of the twelve tombs are distributed in an orderly fashion throughout the room.

In the last quarter of the 19th century, the eighth burial hall was added to the south-eastern corner of the turbah. It is a rectangle-shaped room surmounted by an oval-shaped dome devoid of decoration. It has a number of windows opening onto the street and houses 19 tombs, all of which are devoted to women of the Husaynite House, some of whom are anonymous. The first Princess to be buried in this room was Princess Aisha, daughter of Hussein Bey II, who died in 1887 (1305 AH), and the last one was Princess Hallouma, daughter of Muhammad Al-Habib Bey who died in 1947 (1366 AH). A variety of local and foreign building materials, imported for the purpose, were used to construct and decorate the beys' tourbah. Thus, ochre sandstone brought from the vicinity of Ghar el Melh (northe of Tunis), Khathel stone and plaster were used to decorate the domes and the upper parts of the walls; polychrome glazed ceramic tiles imported from Italy, in addition to tiles made locally in the Qallaline workshops, were used in abundance to clad the walls and floors. Materials imported from Europe, such as Carrara marble and polychrome alabaster, were used to make the door and window frames, while noble woods imported from Venice and Tortosa were used to make the doors. Floors are covered with white marble, while door locks and window grids are made of iron or copper.

The tourbah’s founder, Ali Bey, then the successive Husseinite beys established important waqfs (endowments) inside and outside the medina of Tunis, the revenues of which were used to meet the needs of the tourbah, such as restoration, repairs and lighting. Another part of this revenue was used to pay the salaries of the people in charge of the mausoleum.

With its unique architecture and fine decorations, reflecting a blend of various local and foreign artistic and architectural styles, the Tourbet el-bey remains, to this day, one of the most treasured funerary buildings and historic monuments in the city of Tunis.