Excerpts from Books and Wikipedia
"He was the eldest son of Sebutkigin, a Turkish Mamluk ('slave soldier') who had seized control of the city of Ghazni in southern Afghanistan. Mahmud became emir in 998 and spent most his reign campaigning in Iran, central Asia, and India, building a considerable empire for himself and, through his patronage of the arts--which led to a revival of Persian literature and craftsmanship--turned Ghazni into one of the great cultural centers of the Muslim world. . . . He was the first prominent Turk of the Muslim world, and he firmly established Muslim influence over northern India; . . . In Indian historical traditions, Mahmud has come to be seen as a tyrannical oppressor who used his religion to justify wanton destruction and slaughter of Hindus. Conversely, in Pakistan and Afghanistan, Mahmud is regarded as a hero who fought to spread Islam throughout the Indian subcontinent." [Furtado: 1001 Days]