Where was the seat of power for the Western Church?

Vatican City was the seat of power for the Western Church

Explanation:

'Vatican City' is the seat of power for "Western Church". It is in Rome, on Tibet River's west bank. It is the home for the pope. It is a very small but an independent nation state.

The government of Roman Catholic / church is called "Holy See". Vatican City buildings and gardens are old for more than a century. Also, it has its own telephone, radio system and even separate pharmacy. It is the home for pope and Roman Curia.