 Complete the following phrase:  In 1700, Carl Piper left Sweden in the entourage of Charles XII to participate in the Great Northern War, leaving Christina in charge of the family affairs. She visited him in the Swedish military headquarters on two occasions: the first one in Rawicz in 1705, and the second time in Altranstädt in 1707. On her first visit, she was received by the Polish queen Catherine Opalińska and introduced at the Polish court at Rydzyna Castle. Carl Piper was contemplating to visit Sweden for his health, as he was ill at the time, but she persuaded him to stay. During her second visit, in 1707, Carl Piper was approached by John Churchill, 1st Duke of Marlborough, who allegedly offered him a pension in exchange for advising Charles XII to attack Russia. After the Battle of Poltava, which became disastrous for Sweden, Carl Piper was blamed for having ultimately caused the defeat by persuading Charles XII to the 