Question: Which person that Roger Manvell made a biography of had the middle name of Luitpold? 

Context paragraphs:
Marion Christopher Barry: Marion Christopher Barry was born in June 1980 to Marion Barry and Barry's third wife, Effi Slaughter Barry.  He was their only child.  His father had wanted to name him Marion Barry III, but Effi was strongly opposed, and they decided to give him the middle name Christopher instead.  For most of his adult life, Barry went by his middle name, Christopher.

Latvian name: Latvian names, like in most European cultures, consist of two main elements: the given name ("vārds") followed by family name ("uzvārds").  During the Soviet occupation (1940 - 1991) the practice of giving a middle name was discouraged, but since the restoration of Independence Latvian legislation again allows giving of up to two given names and it has become more common to give a middle name to children.

Chris Funk: Christopher Funk is an American musician and multi-instrumentalist best known as a member of the Portland, Oregon, indie rock band The Decemberists.  He plays guitar, pedal steel, piano, violin, dobro, hurdy-gurdy, mandolin, saxophone, the theremin and many other instruments.  According to Colin Meloy, as stated at the Pilgrimage Festival in Franklin, TN on September 27, 2015, Funk was originally given the middle name "Ryman" but a clerical error on his birth certificate resulted in his middle name being recorded as "Lyman."

Barend: Barend or (somewhat dated spelling) Barent is a Dutch male given name and occasional middle name.  As of 2014, there are over than 4,000 men in the Netherlands with this as their first name, and nearly 3,000 with it as their middle name.  It was likely derived from Bernard.  Notable people with the name include:

Jeff Strabone: Jeff Strabone is a Brooklyn-based American scholar, political activist and civic leader.  In 2016, his website "directelection.org" listed the names and addresses of members of the U.S. Electoral College, and he urged people to write to electors to ask them not to vote for president-elect Donald Trump, an effort which brought him national attention.  As a civic leader in Brooklyn, he has been active in promoting theatre preservation, building codes and housing issues, hospital preservation, and traffic flow.  He has been a leader of Brooklyn's Cobble Hill Association, a neighborhood preservation group.  He is the co-founder and chairman of the New Brooklyn Theatre.  In 2008, he changed his middle name to "Hussein" as a show of solidarity with then presidential candidate Barack Obama, who was running for the office of president, and who had been criticized for his Muslim-sounding middle name.  He is an associate professor of English and teaches British and African literature, and he was granted tenure at Connecticut College in 2016.  He commented about the post-election effort:

Singh: Singh is a title, middle name or surname, which originated in India.  Derived from the Sanskrit word for lion, it was adopted as a title by certain warrior castes in India.  It was mandated by Guru Gobind Singh for all Sikhs.  It was later adopted by several castes and communities.  As a surname or a middle name, it is now found throughout the Indian subcontinent and among the Indian diaspora, cutting across communities and religious groups, becoming more of a title than a surname.

Hess: A Biography: Hess: A Biography is a 1971 biography of Rudolf Hess by Roger Manvell and Heinrich Fraenkel, published by MacGibbon and Kee (London) in 1971 as a 256-page hardcover.  Drake Publishers (New York) republished it in 1973.

Roger Manvell: Arnold Roger Manvell (10 October 1909 – 30 November 1987) was the first director of the British Film Academy (a post he filled for over a decade), author of many books on films and film-making, and authored and co-authored (with Heinrich Fraenkel) many books on Nazi Germany, including biographies of Adolf Hitler, Rudolf Hess, Heinrich Himmler, Joseph Goebbels and Hermann Göring.  During World War II he worked in the Ministry of Information, creating propaganda films for the British government.  In his career, he also lectured in universities in as many as forty countries in three continents (America, Europe and the Middle East), and made a name as a broadcaster and screenwriter.  He joined the Boston University faculty in 1975 teaching film history classes at the College of Communications.  Manvell was named University Professor in 1982.

Heinrich Himmler: Heinrich Luitpold Himmler (] ; 7 October 1900 – 23 May 1945) was "Reichsführer" of the "Schutzstaffel" (Protection Squadron; SS), and a leading member of the Nazi Party (NSDAP) of Germany.  Nazi leader Adolf Hitler briefly appointed him a military commander and later Commander of the Replacement (Home) Army and General Plenipotentiary for the administration of the entire Third Reich ("Generalbevollmächtigter für die Verwaltung").  Himmler was one of the most powerful men in Nazi Germany and one of the people most directly responsible for the Holocaust.

Middle name: In several cultures, people's names usually include one or more names in addition to the portion that is usually considered adequate to identify them.  In a number of cultures where a given name is expected to precede the surname, such a name is likely to be placed after the given name and before the surname, and thus called a middle name.  In English-speaking American culture, that term is often applied (arguably mistakenly) to names, occupying that position, even if the bearer would insist that that name is being mistakenly called a "middle name", and is actually (to mention several types of atypical cases):

Supporting paragraphs: Roger Manvell Heinrich Himmler
Answer: Heinrich Himmler