Maxim Lieber was born on October 15, 1897, in Warsaw, then Congress Poland, to a family of Jewish origin. Both parents came from Opoczno, Poland. His family left Hamburg, Germany for New York City aboard the S. S. Pennsylvania in 1907 and lived in the Bronx. Lieber’s father served as a typesetter for the Yiddish social-democratic newspaper The Jewish Daily Forward, suggesting that one parent (if not both) was secularist. Young Maxim attended public schools, including Townsend Harris Hall (then part of New York City College) and Morris High School (Bronx, New York).

In 1918, Lieber joined the West Ontario Regiment of the Canadian Over-Seas Expeditionary Force. In 1919, he enlisted in the U.S. Army Medical Corps. In 1920, he received an honorable discharge as a Sergeant. (In 1951, Lieber testified that he had served in World War I, stationed at Camp Meade in the replacement battalion in medical service, that he received U. S. naturalization in Washington in 1919, and that he left the U.S. Army as a sergeant in the Army Medical Corp at Walter Reed Hospital.)

In 1924, Lieber married to Irma Cohen, with whom he had one son and whom he divorced by 1933. He married Sally Tanenbaum in May 1936, whom he divorced before 1939. (The marriage though not the dates were corroborated by Whittaker Chambers and his wife during questioning by the FBI in 1951.) Minna Edith Zelinka was a co-respondent in the second divorce; Lieber married her before 1939. They had two children.

After serving in the Army, Lieber helped set up a publishing house, Lieber & Lewis (which Albert Boni took over in 1923). He co-edited a book, published in 1925, and then traveled abroad using the advance paid him by the publisher (R. M. McBride). Returning to the States in 1926, he worked for Brentano’s as head of publishing through 1930. At that point, Brentano’s went into involuntary bankruptcy.

In 1930 Lieber set up the Maxim Lieber Literary Agency. Over the next 20 years, he would represent some 30 clients. In 1931, his office address (advertised in New Masses magazine) was “55 West 42nd St., New York” and telephone Penn. 6-6179.”

J. Peters introduced Lieber to Whittaker Chambers in late 1934. The two became friends, and Chambers often used Lieber’s apartment when visiting New York. Chambers wrote of Lieber (using his alias “Paul”):

In 1949, J. Peters left the United States at his own volition (ahead of near-certain deportation) for Hungary, where he lived for the rest of his life. Shortly thereafter, Noel Field (like Hiss not only as an employee of the U.S. Department of State, but one named by Chambers as part of his spy ring) fled from Switzerland to Poland (behind the Iron Curtain). This left House Un-American Committee (HUAC) with few people who had not yet pleaded the Fifth to corroborate Chambers’ story. On February 27 and March 1, 1950, Sherman appeared before HUAC without counsel and pleaded the Fifth to nearly every question asked him.

On June 13, 1950, Lieber appeared with lawyer Milton H. Friedman (brother-in-law of New York State Justice Philip M. Halpern) before HUAC during executive session with House representatives Francis E. Walter, Burr P. Harrison, and Morgan M. Moulder. As with Sherman, HUAC read out excerpts from Chambers’ testimony that mentioned their names or aliases. They also asked Lieber (as Sherman) whether he knew either Alger Hiss or J. Peters. (Chambers had recounted a meeting between, Lieber, himself, and Hiss on Lieber’s farm: Lieber confirmed only ownership of 103-acre farm in Ferndale, Pennsylvania, in Bucks County from about 1935-1945.) They asked whether his clients included Louis Adamic, Howard Fast, V. J. Jerome, or Paul Robeson. They asked whether he knew Otto Katz (reputed to be involved in the death of Walter Krivitsky and in Soviet attempts to seize Chambers after defection) or Katz’s associate Erwin Kisch. They asked whether he knew Osmond K. Fraenkel or whether he had ever contributed to a publication (probably Freies Deutschland) by Anna Seghers in Mexico. To all such questions, Lieber pleaded the Fifth on the grounds of self-incrimination. As he explained, he had also testified twice already in 1948 before the grand jury in New York City, which then indicted Hiss on two counts of perjury. During testimony, Lieber listed three by name of some 30 clients: Erskine Caldwell, Carey McWilliams, and Robert Coates.

Lieber left the U. S. for Mexico in 1951 with his wife Minna and their two children.

Lieber’s flight abroad in 1951, following Peters, Field, and others, left the U. S. Government with few witnesses to corroborate Chambers’ testimony about Hiss. A second trial had found Hiss guilty of two counts of perjury a few months earlier, in January 1950. Witnesses included Hede Massing and a former housemaid.

According to Chambers in his 1952 memoir Witness, Lieber helped the underground network in New York City. Initially, Chambers secured Lieber’s cooperation in setting up a branch of his agency in London, which Chambers would run under the name of “David Breen.” Then, he secured Lieber’s support for operations in East Asia. During the summer of 1935, the Chambers family lived with the Liebers in Smithtown, Pennsylvania. After Chambers’ defection in 1938, Peters used “Paul” (Lieber) to contact him. Later, when Chambers wanted to let Peters & Co. know about his life preserver (see Pumpkin Papers), he contacted Lieber to relay his message. While the London operation was getting under way (it would eventually fall through), Chambers asked Lieber to cooperate with fellow underground operator John Loomis Sherman (under the alias “Charles Francis Chase” and Chambers as “Lloyd Cantwell”) in establishing the American Feature Writers’ Syndicate.

(In 1952, Nathaniel Weyl would testify further about Hiss.)

In late 1954, on instructions from Moscow, Lieber moved with his family to Warsaw, Poland. They spent the next 14 years in Poland. Professor Erwin Marquit knew the Liebers in Poland and recollects:

After one year in Cuernavaca, Mexico, they moved to Mexico City, where they resided another two years. Following his departure from the US, Lieber was stripped of his US citizenship. He resided in Mexico as a stateless person. The US authorities returned his citizenship in 1964.

In August 1968 they left for the United Kingdom, from where they were expelled by the British Home Office three months later.

Maxim Lieber died age 95 in East Hartford, Connecticut on April 10, 1993.