Roger John Liddle, Baron Liddle (born 14 June 1947) is a British political adviser and consultant who is principally known for being Special Adviser on European matters to Tony Blair and for working together with Peter Mandelson on books outlining the political philosophy of the Labour Party under Blair's leadership. He is now a member of the House of Lords and Chairman of the International Think Tank Policy Network.Liddle was born in Carlisle and attended Carlisle Grammar School. He undertook the Wyndham Scholarship at Queen's College, Oxford, where he also received degrees in Modern History and Management Studies. In 1983 he married the Hon. Caroline Thomson - daughter of Lord Thomson of Monifieth, former Labour Member of Parliament for Dundee East. She is currently Chief Operating Officer of the BBC, having pursued a career in journalism. They have one son, the Hon. Andrew Benjamin Thomson-Liddle who studies at the University of St Andrews (b.1988).