The Ghaznavids brought Islam to India by "fire and sword" as Mahmud once put it, and returned with fabulous riches taken from both Indian princes and temples. 
During this time visitors to and residents of Ghazni wrote with wonder of the ornate architecture of its buildings, the great libraries, the sumptuousness of the court ceremonies and of the wealth of precious objects owned by Ghazni's citizens.  The seemingly never-ending victories of Mahmud the Ghazni brought incredible wealth and opulence into his power and he transformed the city of Ghazni into a jewel in the crown of the Islamic Caliphate of the 11th century A.D..  By 1040 A.D., a turning point for the worse came with a horrible defeat of the Ghaznavids by the Seljuk Turks which removed all the Iranian and Central Asian region from Ghazni power.    By 1130 A.D., another crushing defeat took away the control of all the Indian territories and the Ghaznavid Empire did all it could to survive until its total eradication in 1186 A.D..

 

 

Extract taken from www.paleodirect.com

The Ghaznavid military was a formidable power.  Its elite palace guard comprised 4,000-6,000 heavy cavalry.  The remaining force brought the total army count to around 30,000 strong.  The Ghaznavid cavalry was armed with recurve bows, maces, battleaxes, long curved swords, and even lances but this varied by soldier depending on their ethnic origin.  Maces were particularly considered a weapon of military prowess and heroism.  Their horses were either lightly or not armored at all.

Regular infantry wore chain mail coats and carried metal shields covered in leather.  They were equipped with long recurve bows and spears and for close hand-to-hand combat, they carried a mace or short sword on a belt.  The regular foot auxiliary soldiers sometimes fought on camels, horses or mules but often would dismount and fight on ground once fully deployed.  Subordinated Hindu princes were required to pay tribute in elephants and large annual counts were held where as many as 1670 "battle-ready" elephants were documented.  A standing force of 1000 elephants was kept at Ghazni.  Historians have recorded forces of 400-700 elephants in individual battles, with each elephant bearing a crew of four spearmen or archers.  The Ghaznavid baggage trains also employed elephants.  Their war elephants were fearsome military weapons, heavily armored with castle-like structures on their backs housing the soldiers and with heavy plate armor protecting their bodies.  Their tusks were even equipped with poison covered giant blades.  War elephants were often used as individual mobile independent forces with a supporting mini-army and cavalry of warriors.  Riskier but more effective tactics employed the elephants in solid battle lines where they charged into the center of an enemy force and literally crushed and destroyed paths of all that got in their way.