Explanation:

• Mahmud of Ghazni
• Most scholars, including al-Biruni, were taken to Ghazni, the capital of the Ghaznavid dynasty.
• Biruni was made court astrologer and accompanied Mahmud on his invasions into India, living there for a few years.
• He was forty-four years old when he went on the journeys with Mahmud of Ghazni.