He migrated to Perth in 1896, worked for the Police Department and active in community life in Subiaco. Henry Dalgish was elected in 1901 as the first member for the Subiaco seat and in 1903 became leader of the small Labor Parliamentary group. As a more conservative public servant he stood apart from his colleagues who were trade unionists from mining seats. After the 1904 election Dalgish led a 23-strong Labor Party and became the first Western Australian Labor premier at the head of a government depending on the support of a group of conservative Independents. His inexperienced Government also suffered from internal dissension and after 12 months in August 1905 was defeated in Parliament by the rejection of a Bill to buy the Midland Railway Company. Henry Daglish resigned as Labor leader the following month and quit the ALP. He was re-elected for Subiaco in 1905 as an Independent and in 1908 was elected comfortably as its Liberal member. In 1910 he was appointed Minister for Works in the Wilson Liberal Government. However in 1911 the government was defeated at the polls and Daglish lost his seat. From 1912 he worked as an estate agent, and was the employers' representative on the State Arbitration Court.