Opposite the Green Mosque is the Yesil or Green Türbe (tomb) for Mehmet I. It dates from the early 15th century. This is a detail of its entrance.

This mausoleum was ordered by Mehmed I Çelebi in 1421, forty days before he died from a heart attack during a hunting party. His son and successor Murad II saw to its completion.

On the picture: The inscription above the entrance is written in elegant ‘sülüs’ script.

Sülüs (from Arabic: ثلث‎ ṯuluṯ "one-third"), also referred to as ‘thuluth’, is a script variety of Islamic calligraphy invented in Persia, which made its first appearance in the 11th century AD. The straight angular forms of the older Kufic script were replaced in the new script by curved and oblique lines. In Sülüs, one-third of each letter slopes, from which the name (meaning "a third" in Arabic) comes. It is a large and elegant, cursive script, used in medieval times on mosque decorations.

Correspondent: J.M.Criel, Antwerpen.
Sources: ‘Bursa Yeşil Külliyesi’ (Erdem YÜCEL, Arkeolog) – Wikipedia
& ‘Website of ‘osmanli-devleti 1299.tr’