Beltharius was author of the Chronicles of Beltharius, being the only Elf to have left any recordings of visiting an actual Lizardman city, having barely survived the attempt. He was the captain of the explorers that visited the Golden Pyramid of Pahuax back during the reign of Bel Shanaar, being one of the few to fight their way out of the city when the "great toad-god" that ruled it had turned nasty. The tale is well known by the Asur, with Beltharius' original journals residing in the White Tower of Hoeth.[1a]
It is also from the Chronicles of Beltharius that skinks are named and codified as servants of the Slann, rather than being Slann themselves. It's also from Beltharius that the temple-city of Zultec is known as a satellite settlement to Pahuax.[1a]