Complex sentence: The feathered helmet from the British Museum was chosen to be one of the History of the World in 100 Objects which was a series of radio programmes that started in 2010 and that were created in a partnership between the BBC and the British Museum.
Split into simpler sentences: The feathered helmet from the British Museum was chosen to be one of the items featured in the radio series "A History of the World in 100 Objects". The series started in 2010 and was created in a partnership between the BBC and the British Museum.