Why did Noland take the king to the city of gold?

I think he wanted to meet his friends, first and foremost. But the story was odd to me as well, for the same reasons. It did however sound he was at the same time deeply loyal to his king, but I may be misremembering.

I agree Noland mostly wanted to see his friends again and maybe get proof of his discovery. The only way to secure funding for the expedition was to promise the king a nice payout. In real life explorers often had to make bold claims about the rewards of voyages in order to get funding. It costs hella cheddar to supply and crew a ship for a voyage of potentially years. Noland didn’t have that kind of scratch and so the King could dictate some terms.