Junayad al-Abbasi, (fl. ca. 825) was chosen by Abbasid caliph Al-Mamun as the governor of Sindh. He fortified the city of Mansura after a series of Brahman raids he gathered various Sindhi Muslim Tribes at Nerun (modern day Hyderabad, Sindh) there he built a garrison and provided cavalry training to various Muslim tribes.
In the year 825, he started an expedition from Nerun he commanded a large army under the Abbasid flag against the Hindu Brahman temple at Somnath.
Ibn Hawqal provides a detailed account on his expedition and also illustrates the earliest map of Sindh, which stretched from Debal to Kashmir.
References
Junayad al-Abbasi Wikipedia(Text) CC BY-SA