What branch has the power to try all impeachments

Because the Constitution both provides the Senate with the "sole power to try impeachments" and empowers "Each House ... to determine the Rules of its Proceedings," the Senate has formulated its own special impeachment trial procedures (first written down by Thomas Jefferson when he was Vice President). In President Johnson's impeachment trial, the Senate formulated an additional set of rules that have largely remained intact ever since and were followed by the Senate in President Clinton's impeachment trial.

The Senate has the sole Power to try all Impeachments.