Diana Princess Of Wales Althorp House Fountain Pen Set. This is handcrafted pen set in commemoration of the late Diana Princess of Wales who was buried at her family home. Althorp House, Northamptonshire, England on 6th September 1997. This pen set is in a purple velvet-covered box and consists of handcrafted high quality fountain pen and matching ballpoint pen. Manufactured by English luxury pen company Conway Stewart who went out of business in 2014.