I want to know the answer to the following question:
The royal courts sponsored both Buddhism and what?
All the background I'm provided with is that "The Mañjusrimulakalpa, which later came to classified under Kriyatantra, states that mantras taught in the Saiva, Garuda and Vaisnava tantras will be effective if applied by Buddhists since they were all taught originally by Manjushri.". Is that enough to answer the question?
Answer: no