Consists of source material passed on to JA by J L Garvin, and Garvin's and JA's drafts, typescripts and proofs for JA's continuation of Garvin's official biography of Joseph Chamberlain. Garvin had finished the first three volumes between 1932 and 1934, but died in 1947 before he could complete his work. Initially, JA was supposed to end the biography with volume IV, so much of the material in this series relates to this volume, "1901-3: At the Height of his Power", which was published in 1951. However, he still had a lot of material left to cover, but was increasingly involved in his own career, so eventually published volumes V and VI, "1901-14: Joseph Chamberlain and the Tariff Reform Campaign" 18 years later in 1969.