The Romanian "Steel Crown" is the crown that was used for the coronation of Romanian kings. It was cast of steel from a Turkish cannon that was captured by the Romanian Army during the Siege of Plevna in the Romanian War of Independence (1877-1878). King Carol I chose that the crown be made of steel, not gold, to symbolize the bravery of the Romanian soldiers. In addition to the absence of gold, the crown contains no precious stones. The crown was presented to the king on May 10, 1881, during the ceremonies of his coronation and of the proclamation of Romania as a kingdom. On October 15, 1922, the crown was used for the coronation of King Carol I's nephew and successor, King Ferdinand I, as well as the coronation of Romania's last king, Michael I, on September 6, 1940. The planned September 1930 coronation of Ferdinand's son, King Carol II, who was the father of King Michael I, never occurred because of his relationship with Magda Lupescu.