Most Orthodox churches are aligned with Rome once again. The RCC is actualy the Latin Church (Western Rite) and is part of the True Catholic Church as are the 22 Eastern Rite Churches. Together they constitute the largest Christian denomination and are often referred to as the Mother Church as they are the Originl Christian Churches. There are more than one billion members and are a growing church.
Separately there's that 'primacy' claim and I don't think that will ever be resolved.