The Upright Man was a title given to the leader of the Mockers.
The first Upright Man, the father of Jimmy the Hand and Lysle Rigger, was a chandler named Donald. He is against Guy du Bas-Tyra's secret police led by Jocko Radburn, and with smuggler Trevor Hull, helped Princess Anita and Arutha escaped out of Krondor.
After Arutha became the Prince of Krondor, he asked for the Upright Man's help in flushing out the Nighthawks. In exchange, he wanted Arutha to take Jimmy as his squire. For the following years, the Crown and the Mockers had good dealings with each others.
Lysle initially called himself the Sagacious Man, but, at Jimmy's urging, changed his name to the Upright