How many ecumenical councils are there?
There are 21 ecumenical councils recognized by the Roman Catholic Church. The first Council of Nicaea, was called by Emperor Constantine and ratified by Pope Sylvester in A.D. 325. The last Catholic ecumenical council was held in St. Peter’â„¢s Basilica in the Vatican from 1962 to 1965, and is called the Vatican II. This is according to the site Catholicism.org.