The Royal Club was the first who managed to defend his title of the winners of the Champions League.
In the final of the Champions League 2016/2017 Real Madrid beat Juventus 4: 1.
Thus, Zidane's wards managed to win the Champions League in the second season in a row.
None of the teams could achieve such an achievement (meaning the Champions League, not taking into account the European Champions Cup, which was held before 1992).
If you take into account and the European Cup, then to protect the title of the main team of the continent could all the same Real (permanent victories from 1956 to 1960), Benfica (1961-1962), Inter (1964-1965), Bavaria (1974-1976 ), Liverpool (1977-1978), Nottingham Forest (1979-1980) and Milan (1989-1990).
On the account of Real 12 wins in the main European Cup: 6 in the European Cup and 6 in the Champions League.