[2] He married Dr Margaret Pearse, senior resident physician of the Canning Town Medical Mission Hospital, in 1899 and they had three daughters.

In 1902 he became secretary of the National Unemployed Committee, and in 1903 joined The Rainbow Circle, a progressive discussion group of Liberals and Socialists.

As an MP, he took a strong interest in civil liberties (pressing for Hindu interpreters in British prisons, for example), international issues and unemployment.

He was chairman of the Save the Children Fund, administered a number of educational trusts for the underprivileged and worked with groups for the relief of refugees.

[2] He supported the garden city movement and land settlement, as well as putting a case for farm colonies to train the unemployed.

[1] Alden died during the Second World War when a German V-1 flying bomb exploded in Tottenham Court Road on the morning of 30 June 1944.

A Percy Alden Scholarship, to enable a student to attend university followed by a year's training in social work, was established in his memory.