Arthur Stanhope Aldrich was born in Dublin in 1872. He spent four years in Japan before being sent to Paris to be educated at an Anglo-French College there. In 1886, he came to New Zealand, where his father purchased several properties, including "Matsubara", near Bunnythorpe.
Aldrich was a keen athlete, and distinguished himself in several branches of sport. He was a rifleman, an angler, and a huntsman. He was a full private of the Manawatu Mounted Rifle Corps from the time it was organised, in 1891, working his way through the ranks to hold the commission of lieutenant.