Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The men's 4 x 400 metres relay was a track and field athletics event held as part of the Athletics at the 1912 Summer Olympics programme. It was the debut of the event, which along with the 4x100 metre relay marked the first relays of equal legs in the athletics programme (a medley relay had been held in 1908). The competition was held on Sunday, July 14, 1912 and on Monday, July 15, 1912. Twenty-eight runners from seven nations competed.