After the decline of the Pushyabhuti dynasty, the kingdom that continued to be a significant power was Kanyakubja.

Reasons for the significance of Kanyakubja:

- Geographical Location: Kanyakubja, also known as Kannauj, was strategically located in the fertile Gangetic plains of present-day Uttar Pradesh. This location allowed it to control important trade routes and agricultural lands, making it a prosperous and influential kingdom.

- Political Stability: Despite the decline of the Pushyabhuti dynasty, Kanyakubja managed to maintain political stability and governance. This stability helped the kingdom continue to wield power and influence in the region.

- Cultural Influence: Kanyakubja was a center of culture and learning in ancient India. It was known for its patronage of the arts, literature, and philosophy, attracting scholars and artists from far and wide. This cultural influence further enhanced the kingdom's prestige and power.

- Alliances and Diplomacy: Kanyakubja was adept at forming alliances with neighboring kingdoms and engaging in diplomatic relations. These alliances helped the kingdom consolidate its power and maintain its position as a significant player in the political landscape of ancient India.

- Economic Prosperity: The kingdom of Kanyakubja was economically prosperous, with a thriving trade network and agricultural economy. This prosperity allowed it to exert influence through economic means and further solidify its position as a major power in the region.

In conclusion, Kanyakubja's strategic location, political stability, cultural influence, alliances, and economic prosperity were key factors that enabled it to remain a significant power even after the decline of the Pushyabhuti dynasty.

Kanyakubja continued to be a significant kingdom under rulers like King Yashovarman after the decline of the Pushyabhuti dynasty.