The Origins of Borders

There are 317 land borders in the world, how do we get the idea of borders? Most of these were invented in the late 19th and early 20th centuries. Where did the first international border have it's being? Andorra I think a little country in the Pyrenees. The Arab civilization spreading eastwards from the Nile would encounter the Persian or Mesopotamian civilization spreading west or southwest from Mesopotamia. They meet each other in the salt marshes of southwestern Iraq - near Basra which was a central city in the Aradirak War.