BBC Four HD Tuesday

The former steeplejack examines the development of castles from early Iron Age forts to secret tunnels used during the Second World War, visiting Warwick and Hadrian's Wall

Richard Holmes analyses the Battle of Agincourt, when Henry V's makeshift and massively outnumbered army scored a victory against the French

A massive Rolls-Royce repair bill forces Audrey to revert to real horse power, while DeVere takes to the skies in a new helicopter

Hyacinth cannot suppress her excitement when she hears Emmet is rehearsing an amateur production of The Boyfriend

Clare Jackson examines the history of the royal family and charts the origins of the United Kingdom, beginning with James VI's attempts to unite Scotland and England

Following Dallas businessman Bill Moore as he sets out to make penis enlargement as commonplace as Botox and bring these procedures into the mainstream

Part two of two. Jim Al-Khalili explores the largest known cosmic structures, including, a vast cloud of solar plasma which surrounds and protects the solar system

The team heads to La Palma in the Canary Islands, where giant new telescopes and cutting-edge science are opening extraordinary new windows on the universe

The former steeplejack examines the development of castles from early Iron Age forts to secret tunnels used during the Second World War, visiting Warwick and Hadrian's Wall

Richard Holmes analyses the Battle of Agincourt, when Henry V's makeshift and massively outnumbered army scored a victory against the French

Clare Jackson examines the history of the royal family and charts the origins of the United Kingdom, beginning with James VI's attempts to unite Scotland and England

Part two of two. Jim Al-Khalili explores the largest known cosmic structures, including, a vast cloud of solar plasma which surrounds and protects the solar system