as vassal rulers under the Guptas - took advantage of the weakening of central authority, broke away and established control over large areas of northern India. Under the Maukharis, Kannauj continued to grow in importance and prosperity. It became the greatest city of Northern India under Emperor Harsha (r. 606 to 647 CE) of the Vardhana dynasty, who conquered it and made it his capital. Chinese pilgrim Xuanzang visited India during the reign of Harsha, and described Kannauj as a large, prosperous city with many Buddhist monasteries. Harsha died with no heir, resulting in a power vacuum until Maharaja Yashovarman seized power as the ruler of Kannauj. The Kannauj Triangle Kannauj became a focal point for three powerful dynasties, namely the Gurjara Pratiharas (r. 730-1036 CE), Palas (r. 750-1162 CE) and Rashtrakutas (r. 753-982 CE), between the 8th and 10th centuries. The conflict between the three dynasties has been referred to as the Tripartite struggle by many historians. There were initial struggles but ultimately the Gurjara Pratiharas succeeded in retaining the city. The Gurjara-Pratiharas ruled Avanti (based at Ujjain), which was bounded to the South by the Rashtrakuta Empire, and the Pala Empire to the East. The Tripartite struggle began with the defeat of Indrayudh at the hands of Gurjara-Pratihara ruler Vatsaraja (r. 780-800 CE). The Pala ruler Dharampala (~770-821 CE) was also keen to establish his authority at Kannauj, giving rise to a struggle between Vatsaraja and Dharmapala, in which Dharmapala was defeated. Taking advantage of the chaos, the Rastrakuta ruler Dhruva Dharavarsha (r. 780–793 CE) surged northwards, defeated Vatsaraja, and took Kannauj for himself, completing the furthest northern expansion by a South Indian ruler. When the Rashtrakuta ruler Dhruva Dharavarsha advanced back to the south, Dharampala was left in control of Kannauj for some time. The struggle between the two northern dynasties of Palas and Gurjara Pratiharas continued: the Pala's vassal Chakrayudha (Dharmapala's nominee for Ujjain) was defeated by the Pratihara Nagabhata II (r. 805–833 CE), and Kannauj was again occupied by the Gurjara Pratiharas. Dharmapala tried to take control of Kannauj but was defeated badly at Moongher by the Gurjara Pratiharas. However, Nagabhata II was in turn soon defeated by the Rashtrakuta Govinda III (r. 793–814 CE), who had initiated a second northern surge. An inscription states that Chakrayudha and Dharmapala invited Govinda III to war against the Gurjara Pratiharas, but Dharmapala and Chakrayudh both submitted to