After over a decade in the second tier of English football , Brian Clough took Conquering charge at Derby and kickstarted Process_start a revolution Change_of_leadership at the club ; it went on to win Getting the Football League First Division twice in the 1970s and reach Arriving the European Cup semi finals Competition in 1973 before rapidly declining Cause_change_of_position_on_a_scale back to the third tier and near financial meltdown within ten years of its second Championship .