Constantine had active diplomatic relationships with foreign courts, including those of the caliph of Cordoba Abd ar-Rahman III and of Otto I, Holy Roman Emperor. In the autumn of 957 Constantine was visited by Olga of Kiev, regent of the Kievan Rus'. The reasons for this voyage have never been clarified; but she was baptised a Christian with the name Helena, and sought Christian missionaries to encourage her people to adopt Christianity. According to legends, Constantine VII fell in love with Olga, but she found a way to refuse him by tricking him into becoming her godfather. When she was baptized, she said it was inappropriate for a godfather to marry his goddaughter.