To me, both of these fallen cities has always felt Shuriman, but looking at the old map they are both considered their own areas. What do you think Riot's take on them is in the new lore? Shuriman this time, independent or something else? With the runewars now seemingly not canon anymore, at least Urtistan need a new excuse to have fallen (and the fall of Shurima seems like a pretty logical one).
According to the map, they're on opposite sides of the Shurima Desert. :P
Icathia might've happened earlier or later, but I guess Urtistan could've been a Shuriman client state that collapsed some time after Shurima.
There is an obscure reference on the Ascension Game Mode-tab on the Shurima Promo Page.
"THE SUN DISC WAS ANCIENT EVEN THEN. WE KNEW OF ITS POWER, MY BROTHER AND I, AND SHURIMA FACED A DIRE THREAT, FROM MYSTERIOUS BEINGS UNLIKE ANY WE HAD EVER KNOWN."
So Nasus and Renekton ascended to combat an invasion of sorts way way before Azir's time. The "mysterious beings" could have been void creatures. It is possible that Icathia, maybe then a part of Shurima, was the scene of this battle, later abandoned for some reason. Supposedly it is now claimed by the void.
