“Roman Church” was what the Western Church called itself in the Councils before protestantism. They also called themselves “Latin Catholics” as opposed to Greek Catholics, Coptic Catholics, etc. The protestants coined the term, “Roman Catholic”.
“However, as a result of this decree, let no prejudice arise to the canons and other ecclesiastical constitutions according to which the decision of the greater and senior part should prevail, because any doubt that can arise in them can be settled by a higher authority; whereas in the
Roman church there is a special constitution, since no recourse can be had to a superior.” - Third Lateran Council (AD 1179), Canon I
papalencyclicals.net/Councils/ecum11.htm
“He dictated a letter, which he signed with his own hand, in which he firmly confesses that he holds the faith held by the
Roman church, which is by God’s plan the mother and mistress of all the faithful.” - Fourth Lateran Council (AD 1215), Constitutions 2
papalencyclicals.net/Councils/ecum12-2.htm
“Also, the said metropolitan and bishop and their successors are forthwith to be preferred in each and every honour to bishops who are separated from the communion of the holy
Roman church.” - The Council of Florence (AD 1445), Session 14
papalencyclicals.net/Councils/ecum17.htm