On 13 September 1959 , Olympiacos made its debut in Europe against Milan for the 1959 -- 60 European Cup .
On 13 September 1959 , Olympiacos became the first Greek club that ever played in the European competitions .
On 13 September 1959 , Olympiacos made its debut in Europe against Milan for the 1959 -- 60 European Cup and became the first Greek club that ever played in the European competitions .