Who was Mahmud of Ghazni? Why did he invade India?

Mahmud of Ghazni was son and successor of Subuktagin, the king of Ghazni. He wanted to make Ghanzi the most powerful kingdom in the area. For this he required a large, well-equipped army which could be maintained by large amounts of money. Since he has heard of India's wealth, he decided to raid India and plunder her wealth. He did not want to establish direct rule in India.