It was the new director who turned the company around.

It 虚主语，was be 动词过去式，the 冠词 + new 形容词 + director 名词分别括号，共同构成被强调的名词短语，who 引导从句。整句为 It-cleft 强调结构，突出'新任主管'而非其他因素让公司扭亏为盈。