Who is the person that was sent to Wittenburg to sell letters of indulgence?

Johann Tetzel was the person sent to Wittenberg to sell letters of indulgence. He was a Dominican friar whose aggressive promotion of indulgences in the early 16th century sparked significant controversy and ultimately contributed to the Protestant Reformation. Tetzel's famous slogan, "As soon as a coin in the coffer rings, the soul from purgatory springs," epitomized the practices that Martin Luther and others opposed.