The ancient Greek Olympic games lasted for close to 1200 years. Unless your definition of ongoing is longer than that, I think they qualify.
The ancient Olympics carried a truce enforced by Zeus, unless your definition of international doesn't include "independent political entities who engaged in war" I think they qualify.
Ongoing international games as we understand them are a new phenom, dating back to the mid 19th century, and then only a few games.
The modern Olympics are not that old.
There were almost no such games for most of antiquity until late into the Enlightenment.