Hyamson was born in London and educated at
Swansea Grammar School and Beaufort College, St Leonards. He entered the Civil Service in 1895, where he initially worked at the
Post Office. During the First World War, Hyamson was one of the most active Zionist writers in the UK. His work had been published by the Anglo-Zionist lobby group, the British Palestine Committee, the Zionist leadership in London and the British press.
Lloyd George even claimed that one of Hyamson's articles in the
New Statesman had stimulated his interest in Zionism. During the
First World War, Hyamson was a close associate of
Chaim Weizmann. In April 1917, Hyamson was made the editor of
The Zionist Review (the newspaper published by the
Zionist Federation). In October of that year
Ze'ev Jabotinsky proposed a Jewish Bureau for the UK government's
Department of Information, however as Jabotinsky was preoccupied with organising the
Jewish Legion, the role fell to Hyamson. His work at the Bureau in December 1917 involved distributing news items that illustrated the British government's support for Zionism and the growing support for Zionism among the world's Jews. The main focus of his output was in America, where he distributed cables to two Jewish daily newspapers,
The American Hebrew and
American Jewish Chronicle. At the same time, Hyamson became a senior member of a new committee created by the London Zionist Federation designed to publicise the Zionist message. The Jewish Bureau in the Department of Information and the London Zionist Federation ran in close contact, with members of the Federation writing much of the material for the Bureau. This enabled the Department of Information to hide the official nature of its propaganda, and allowed Zionists to produce material to promote their movement. Examples of Hyamson's work for the Department of Information included
Great Britain and the Jews, a pamphlet he wrote in response to the
Balfour Declaration of 1917 that explained how the agreement was a part of a long tradition of British sympathy for the Jews. A film
The British Re-conquering Palestine for the Jews, made after
General Allenby had taken
Jerusalem, which was sent to Jewish centres around the world. His book
Palestine: The Rebirth of an Ancient People set out "the benefits the recent Jewish colonisation of Palestine has brought to the land". Hyamson also made Jabotinsky the official British journalist for Zionist affairs in Palestine.
Sir Herbert Samuel, the British High Commissioner of Palestine, made Hyamson Commissioner for Migration of the
British Mandate for Palestine in 1921 which put him in charge of the Palestinian Administration's immigration department. Samuel reasoned that like himself, Hyamson was a Zionist, but would not give preference to these interests over those of the government. His attempts to administer British immigration quotas earned him a bad reputation, at least in
Vilnius, where he was known as a 'Jewish anti-semite'. According to
Edwin Samuel, the son of Sir Herbert, who worked with Hyamson in 1926, Hyamson had a "jaundiced view of his own staff: none, even the most senior, was allowed much discretion". He worked late into the night on immigration applications, deciding many of them personally. For
Sir Ronald Storrs, Hyamson was one those Jews (like
Norman Bentwich) whose work for the Administration of Palestine put him in an impossible position where he was criticised by both Arabs and Jews. He felt that Hyamson's attempts to apply the immigration regulations made him very unpopular with pan-Zionists despite having admitted many thousands of Jews. In the summer of 1926 Hyamson went on a tour of centres of Jewish population in Eastern Europe to investigate the conditions of the countries sending the largest numbers of immigrants to Palestine. In 1928, he published a travel guide,
Palestine Old and New, which The Times described as "the work of a Zionist but one who is a born traveller, with an eye for scenery and a taste for romance." ==The bi-nationalist of the 1930s and 1940s==