He was the son of Edward Picken and Frances Margaret Picken. In 1901 the family were living in house 124, Oldcastle, Oldcastle, Co. Meath.
By 1911 the property is described as house 108, Oldcastle Town, Oldcastle, Co. Meath. Picken is described as a Bank Clerk.
The Belfast Banking Company 'Roll of Honour' booklet records Picken as having been 'previously wounded' with his last known address 'in France'.
The National Archives records a Medal Index Card as follows:
Royal Inniskilling Fusiliers
John Eadie, a descendant of Picken has provided the following additional information:
"Hi! Paul Hartley Picken married my great aunt Louie Kells (aged 17 in 1911) in Oldcastle, Co. Meath, Ireland and resided in Winnipeg, Manitoba, Canada for many years, working as an Accountant. He died on the 21st June 1970 in Deer Lodge Hospital, in Winnipeg and is buried in Brookside Cemetery in Winnipeg in a military grave."