Chief Judge Rauf Abd al-Rahman wasted little time on Sunday in reinforcing that image when the trial resumed after a five-day postponement.
He dismissed one defence lawyer, prompting a walkout by the others.
Abd al-Rahman simply appointed new lawyers and the hearing resumed.
In doing so, the judge, 64, established a style markedly different from his predecessor and fellow Kurd Rizgar Amin, who resigned this month after criticism for allowing Saddam and other defendants to use the trial as a platform for diatribes against the US and Iraqi leadership.
Umar Abd al-Rahman, a lawyer and colleague of the new judge in al-Sulaimaniya in the 1970s, said: "He is a serious and honest person.
"He is a man of principles, but sometimes he get nervous quickly."
Lawyer Tariq Harab, who worked with Abd al-Rahman in the 1980s, remembered him as "a good and professional lawyer with great knowledge of law".
"He is a man of principles, but sometimes he get nervous quickly"
Umar Abd al-Rahman,
"I can say that he is an honest and balanced person," Harab said.
"Today, he is trying to correct the faults that accompanied the previous sessions. His seriousness shows that he is an efficient and controlling judge who refuse to turn the court into a field to exchange slanders."
Harab said the new, tough style "should have been adopted right from the beginning".
Abd al-Rahman was born in 1941 in Halabja, the Kurdish town which won infamy when Kurds were gassed there in the 1980s, killing thousands. The judge lost some relatives in the attacks but not members of his immediate family.
He graduated from Baghdad University's law school in 1963 and worked as a lawyer in Baghdad and in the Kurdish city of al-Sulaimaniya until he was appointed as the head of the Kurdistan Appeals Court in 1996.
The court sits in part of the Kurdish self-ruled area of the north, which was beyond the control of Saddam's government after it was established in 1991 under US and British protection.
He is the father of two sons and one daughter.