Sir Ernest Shackleton is the best  example of strong  leadership in times of  change and adversity.
While leading the British Imperial Trans-Antarctic Expedition to be the first over-land crossing of Antarctica, his very sturdy ship became frozen in solid pack ice. Over the course of  nearly two years, Sir Ernest led his team of 27 men through complete isolation, dwindling supplies and impenetrable ice. Yet, his team remained cohesive, congenial and alive. His leadership maintained his crew's optimism, realism, and the attitude to never give up. He led his team through incredible adversity and although the mission failed, they never made it to the continent, he managed to bring 100 percent of his crew back alive (Dennis T. Perkins in Leading at the Edge). I want to be THAT kind of leader....