Jalāl al-Dawlah Malik-shāh (Persian: ملكشاه, Modern Turkish: Melikşah, or simply Malik Shāh) was born in 1055 and succeeded his father, Alp Arslan, as the Seljuq Sultan in 1072, and reigned until his death in 1092.

Following his father's assassination, Malik was challenged in battle by his uncle, Kavurt. In January 1074, their armies met near Hamadan, Kawurd's troops consisting of the traditional Turkmen elements from Alp Arslan's army, while Malik's consisted of ghulams and contingents of Kurdish and Arab troops. Due to Turkmen defections to Malik's army, Kawurd was defeated and, despite Malik's consideration for mercy, later poisoned, presumably on the orders of vizier Nizam al-Mulk.

Although Malikshah was the nominal head of the Seljuq state, his famous vizir Nizam al-Mulk held near absolute power during his reign. Under Nizam's guidance the Seljuq armies contained the Ghaznavids in Khorasan, rolled back the Fatimids in Syria, defeated the Seljuq pretenders to the throne, reduced Georgia to a tributary state, compelled the submission of regional governors, and kept the Abassid Caliphs in a position of impotence. Alp Arslan's victory at Manzikert in 1071 was followed up by a Turkish invasion of Anatolia. This invasion was the work of independent Turkmen armies, such as that of Atsiz ibn Uvaq, and not of the Seljuk army. As a result, the Sultanate of Rum, as the new state was called, did not acknowledge the authority of the House of Seljuq.