A messiah is a king, so who was heir to Jesus's throne?

It's not that Jesus "was" the Messiah, He IS the Messiah! He may not be walking the earth as he did 2,000 years ago, but He is very much alive and sitting at the right hand of the Father in heaven. He needs no heir to His throne as he is sitting on it. He is the King of kings, the LORD of lords, He shall reign forever and ever. Amen.