From the longer Wikipedia page [1]
He was son of Henry Christian Allhusen. Born in Gateshead, he was educated at Cheltenham College and at Trinity College, Cambridge (matriculated 1887, B.A. 1890).
He was commissioned in 1900 as a 2nd Lieutenant in the 1st Newcastle upon Tyne (Western division, Royal Garrison Artillery) Volunteers and later served as a lieutenant in the 2nd Royal Bucks Regiment of Yeomanry and as a Justice of the Peace for Buckinghamshire. He was elected at a by-election in January 1897 as the Member of Parliament (MP) for Salisbury, following the resignation of the Conservative MP Edward Hulse. He did not contest Salisbury at the 1900 general election, when he was elected as the MP for Hackney Central. He was defeated at the 1906 general election, and did not stand again.
He was appointed as a Deputy Lieutenant of Buckinghamshire in January 1897, and was High Sheriff of Buckinghamshire in 1913.