Who were the worst leaders you ever had?

The worst leader (boss) I have had in my 38 year career was the owner of a company I worked in for 5 years. The level of arrogance was breath-taking. He was unwilling to listen or consider any advice as his agendas were already set. He had absolutely no interest in his staff and their well-being. He was determined to pay the absolute minimum possible and would never have considered any kind of financial reward in years where expectations were exceeded. He would never have considered playing to a staff member's strengths but seemed to take pleasure in focussing on their weaknesses and forcing them into doing the things they were least comfortable with within their role. He couldn't even manage to wish his staff a Happy Christmas and to thank them for all their hard work during the year. Inevitably, morale was truly appalling - I have never worked with so many unhappy people and that definitely stemmed from the top.