Husain began his reign by leading expeditions against Darya Imad Shah and Makhdum Khwaja-i-Jahan who had given shelter to his brothers Ali and Muhammad Baqir. They fled to Bijapur where their cause was espoused by Ibrahim Adil Shah.

The arrival of two influential nobles of Nizam Shahi court, Khwaja Jahan Deccani and Saif Ali-ul-Mulk in Bijapur prompted Ibrahim Adil Shah to actively support the cause of Ali. It was agreed that if he would succeed in getting the throne for Ali, the forts of Sholapur and Kalyani would be given to him.

On this understanding, he led an expedition to Ahmadnagar but was defeated. Suspecting the treachery of Ain-ul-Mulk, Ibrahim fled from battlefield. Nizam Shah conquered the forts of Antur, Galna and Baglana.

After signing a treaty of friendship with Ibrahim Qutb Shah, he besieged Gulbarga but abandoned the siege after the arrival of Ramaraj, King of Vijayanagar. Ramaraja mediated between the contending parties and peace was arrived at.