Yakub I of Germiyan

Muzaffar al-Din, Yakub I's paternal grandfather,[3] was tasked with subduing Baba Ishak's rebellion in the area around Malatya.

During the chaos caused by the Anatolian campaign of the Mamluk Sultan Baibars of Egypt in 1277, Ala al-Din Siyavush, commonly known as Jimri, who was a pretender to the Seljuk legacy, revolted against the Mongols.

[4] Although Jimri and Mehmed were eliminated, the Karamanids' presence in Anatolia persisted, signaling further division in the region, which was symptomatic of the downfall of the Seljuks.

The conflict between the Germiyanids and the Seljuks went dormant upon Mesud II's death, and Yakub agreed to become a vassal of the new ruler, Kayqubad III.

[4] Contemporary historian al-Umari described Yakub as the most powerful Turkish emir, being the suzerain of many of his neighbors, with the Byzantine Empire paying him 100,000 pieces of gold each year.

[4] Yakub had hostile relations with the Ottoman state, and provoked the Tatars of the Chavdar [tr] tribe near Karacahisar to attack them in 1313.

Yakub's son-in-law, who was the lord of Afyonkarahisar, fled to Kütahya from Eretna, who was an officer under Timurtash tasked to capture the city.

In the inscriptions of the castle of Sandıklı, which were later moved to a nearby fountain, he was referred to as Sultan al-Germiyaniyya Chelebi al-Azam azzamallahu kadrehu.