The Dravidians While the Guptas ruled in the north, the southern half of the Indian subcontinent was ruled by a separate series of dynasties. One, the Chalukyas (6th-8th centuries AD) expanded south from the Deccan plateau and formed a large but far-flung and volatile dominion. As time wore on, a new power came into being: the Rashtrakuta dynasty (8th-10th centuries), which formed a considerably more powerful state. For generations, the Rashtrakutas vied with the Bengali Palas and the Gurjara Pratiharas for supremacy in the so-called Kannauj Triangle. Alongside the Rashtrakutas rose another entity, the Pandyas (6th-10th centuries) of south India. Under able rulers such as Kadungon and Srimara, the Pandyas ruled much of the coast along the Bay of Bengal, engaging at times – not always by choice – in the Kannauj Triangle rivalry. The region that they ruled was a prominent node along a healthy trade network spanning the Indian subcontinent and its surrounding oceans. However, both realms nearly faced ruin and narrowly avoided catastrophe when the Pala Emperor Devapala launched an ambitious campaign to the far south to expand his already vast realm. The power vacuum and instability created by this and other events directly enabled the rise to supremacy of another great power, the Chola Empire (9th-13th centuries). Although based primarily in southern India and Sri Lanka, the Cholas, led by intrepid rulers such as Rajaraja and Rajendra, expanded their sphere of influence northeast to coastal Bengal as well as to Southeast Asia. In one notable conflict, Rajendra Chola allied himself with Suryavarman I of the Khmer Empire to crush Srivijaya, a maritime empire based primarily in Sumatra and Malaysia. The Chola fleet was among the most powerful of its time, being meticulously organized and well equipped. Comprising a wide array of vessel types, it could crush enemy navies in small-scale engagements or swarm and overwhelm them with sheer numbers. Southern India was also remarkably technologically advanced. One of its more famous products was wootz, a predecessor of modern steel. Dravidian weapons fashioned of this substance were stronger, deadlier, and more durable than their counterparts elsewhere. This technology eventually spread along trade routes to the Middle East, where it became known as Damascus steel, and finally into Europe. Weaponry from this region was also innovative in nature: one prominent example is the urumi, a flexible blade that was wielded like a whip. Urumis had an uncanny ability to circumvent defenses and inflict dreadful lacerations. As the Chola Empire declined, a second wave of Pandya dominance replaced it. However, at this time further adversities emerged: scions of the Delhi Sultanate now made regular incursions south in an attempt to conquer the remainder of the Indian subcontinent. Nevertheless, a new power rose in response to these threats: the Vijayanagara Empire (14th-17th centuries). This formidable state harnessed the strengths of its predecessors, but would also import gunpowder weaponry from European merchants who frequented the region. Though successful for a while, Vijayanagara was eventually overwhelmed by the steady pressure of invasions from the north.