
The word ḥilya or hilye is used for two kinds of description of the Islamic prophet Muhammad. The word comes from Arabic and Turkish words for "ornament". In the art of the Ottoman Empire, a hilya is form of graphic art that lays out words about Muhammad in a pattern. In literature, a hilya is a type of Ottoman-Arabic text describing Muhammad.
Muslims in the Ottoman Empire believed that owning and reading a hilya protected them from trouble in this world and the next. They often carried these descriptions, written in calligraphy and illuminated, as amulets. In 17th-century Ottoman Turkey, ḥilān developed into an art form with a standard layout. They were often framed and used as a wall decoration. Early ḥilān only described Muhammad. Later ḥilān described other people from Islamic history and walis (saints).

Hilye, both as a kind of text and as an art form, come from shama'il, the study of how Muhammad looked and behaved. These contained hadiths (writing of early Muslims) describing Muhammad's spirit and his physical body. The best-known and accepted of these hadith are attributed to his son-in-law and cousin Ali. The sources of ḥilān have been the six main hadith books along with other hadith sources. Their authors include Aisha, ibn Abbas, Abu Hurayra, and Hasan ibn Ali. While shama'il lists the physical and spiritual aspects of Muhammad in detail, ḥilān describe these in a literary style.
Although many ḥilān exist in Turkish literature, Persian literature does not have many examples. For this reason, the ḥilya is considered one of Turkey's national literary styles. The Hilye-i Şerif by Mehmet Hakani (d. 1606–07) is considered the finest example of the style. The first ḥilya written in prose form was the Hilye-i Celile ve Şemail-i 'Aliye by Hoca Sadeddin Efendi.
The ḥilya tradition started with descriptions of Muhammad. Later ḥilān were about the first four Caliphs (leaders), Muhammad's companions, his grandchildren Hasan and Husayn, and walis (saints) such as Rumi. Another important ḥilya writer is Neşâtî, whose 184-verse poem describes the physical appearance of 14 prophets and Adam.
Ḥilān can be written as prose or poems (often in the masnavi form). Two other kinds of Turkish Islamic literature, a mevlid (story of Muhammad's life) or a Mirʿajname (stories of Muhammad's visit to heaven) can include ḥilān.

While authors developed hilye as a style of writing, calligraphers and illuminators made it into a decorative art form. These did not picture what Muhammad looked like, but described him so that readers could imagine him. It became common in 17th century Ottoman Turkey to carry around Muhammad's description for protection. Because of the belief that a house with a ḥilya will not see poverty, trouble, fear, or the devil, these texts were displayed prominently in homes. The term 'ḥilya' was used for the art form for presenting these texts. Thus the ḥilya, as a vehicle for Muhammad's presence after his death, was seen as a talisman, protecting a house, a child, a traveller, or a person in difficulty. The hilya is also intended to help people see Muhammad as a link between the sacred and human worlds. It is seen as an opportunity to send him a blessing and to establish a connection with him.
The pocket ḥilān were written on a piece of paper, small enough to fit in a breast pocket after being folded in three. The folding lines were reinforced with cloth or leather. Other pocket ḥilān were made of wood. Hilyes for display on a wall were made on paper mounted on wooden panels. In the 19th century, thick paper sheets were used instead. The top part of ḥilān that were laid on wooded panels were carved and cut out in the form of a crown. The crown part's decorations could have small paintings of Medina, Muhammad's tomb, or the Kaaba.
Ottomans commissioned scribes to write ḥilān in fine calligraphy and had them decorated by illuminators. These panels were often framed and used as wall decorations in houses, mosques and shrines. They play a similar role to images of Jesus in Christian homes and places of worship.: 276 They represented Muhammad's presence without the "graven image" unacceptable to most Muslims. Although not common, some ḥilān are triptychs with foldable side panels, like Orthodox Christian icons.
The first recorded Hilye-i Sherif panel is generally believed to come from the scribe Hâfiz Osman (1642–1698). He was one of the earliest known to make the panels, although another famous scribe, Ahmed Karahisarî, may have created one about a century before. Hafız Osman experimented with pocket ḥilān in his youth; one of these dates from 1668. It is 22 by 14 centimetres (8.7 in × 5.5 in) and its text is in very small naskh script. It has a description of Mohammad in Arabic, and below that a Turkish translation, creating a triangular block of text. The texts at the centre of ḥilān praise the beauty of Muhammad's physical appearance and character.: 273–274

The standard layout for Ottoman ḥilya panels was made by Hâfiz Osman. It contains the following elements:
The rest of the space is taken up with decorative Ottoman illumination. There is often with a border in a contrasting design to the background of the text sections. The "verse" and "corners" normally use a larger thuluth script, while the "head" section with the bismallah is written in muhaqqaq. Unlike the literary kind of ḥilya, the text on calligraphic ḥilān is usually prose. The Turkish names for central parts of the ḥilya are, from top to bottom, başmakam (head station), göbek (belly), kuşak (belt) and etek (skirt). This naming shows that the ḥilya represents a human body.
This standard way of laying out a hilya comes from the late 17th century. Some examples from the 19th century and two made by Hafiz Osman can be seen below.
Not all ḥilān fit this pattern. Later artists have made new versions.

There are several reasons why graphic ḥilān are popular. In most Islamic culture it is not allowed to draw the face of Muhammad. Hilān respecting this rule by describing him in words. Many authors have described the affection of Muslims for Muhammad, which leads them to read about his physical and moral beauty.
Hakani has said in his poem that a house with a ḥilya will be protected from trouble. Another motivation would have been the hadith given by Hakani in the Hilye-i Şerif. This promises great rewards to people who read and memorize Muhammad's ḥilya. It says they will see Muhammad in their dreams and will be protected from disasters. In the "sebeb-i te'lîf" ve "hâtime" section, the writer says why they wrote the ḥilya. Other ḥilya writers express, at the end of the ḥilya, their desire to be liked by Muhammad, the other prophets, or the four caliphs. One ḥilya writer, Hakim, wrote that he wishes that people will remember Muhammad as they look at his ḥilya.
As an art form, ḥilya has mostly been restricted to the Ottoman Empire. A small number of ḥilya panels come from Iran and follow a Twelver Shi'a version of the form. These ḥilān have a Persian translation below the Arabic text and list the names of the Twelve Imams. In the 19th century, some Iranian ḥilān added pictures of Muhammad and Ali to the traditional format. Modern makers of ḥilān include Rasheed Butt from Pakistan and Mohamed Zakariya from the United States.
In Turkey, it is traditional to give a ḥilya panel as a marriage gift. However, this tradition is disappearing. In Istanbul homes, people covered the panels with sheer curtains. Since Osman's time, every Turkish calligrapher has to make at least one ḥilya, using the three scripts: muhaqqaq, thuluth and naskh. As a tradition, each calligrapher has to make a ḥilya panel to get their diploma (icazetname). The art of ḥilya flourishes in Turkey. Modern artists still create ḥilān in both classical and new forms. Modern ḥilān maintain the same essence even while they include abstract or figurative art.