From Pope Benedict XVI's visit to the Cathedral in Cologne during World Youth Day in 2005:
The city of Cologne would not be what it is without the Magi, who have had so great an impact on its history, its culture and its faith. Here, in some sense, the Church celebrates the Feast of the Epiphany every day of the year! And so, before addressing you, dear inhabitants of Cologne, before greeting you, I wanted to pause for a few moments of prayer before the reliquary of the three Magi, giving thanks to God for their witness of faith, hope and love.
You should know that in 1164 the relics of the Magi were escorted by the Archbishop of Cologne, Reinald von Dassel, from Milan, across the Alps, all the way to Cologne, where they were received with great jubilation. On their pilgrimage across Europe these relics left visible traces behind them which still live on today, both in place names and in popular devotions.
In honour of the Magi the inhabitants of Cologne produced the most exquisite reliquary of the whole Christian world and raised above it an even greater reliquary: Cologne Cathedral. Along with Jerusalem the "Holy City", Rome the "Eternal City" and Santiago de Compostela in Spain, Cologne, thanks to the Magi, has become down the centuries one of the most important places of pilgrimage in the Christian West.
I do not want here to continue to sing the praises of Cologne, although it would be possible and meaningful to do so; it would take too long, for it would be necessary to say too many important and beautiful things about Cologne.
However, I would like to recall that we venerate St Ursula and her companions here; that in 745 the Holy Father named St Boniface Archbishop of Cologne; that St Albert the Great, one of the most learned scholars of the Middle Ages, worked here and that his relics are venerated in the Church of St Andrew; that Thomas Aquinas, the greatest theologian of the West, studied and taught here; that in the 19th century Adolph Kolping founded an important social institution; that Edith Stein, a converted Jew, lived here in Cologne at the Carmelite Convent before being forced to flee to the Convent of Echt in Holland to be deported subsequently to Auschwitz, where she died a martyr. Thanks to these and all the other figures, both known and unknown, Cologne possesses a rich legacy of saints.
I would like to add, at least as far as I know, that here in Cologne one of the Magi has been identified as a Moorish King of Africa, so that a representative of the African Continent has been seen as one of Jesus Christ's first witnesses.
You may see images of Cologne Cathedral and the reliquary of the Magi that Pope Benedict references here.
Happy Epiphany! Merry Christmas! Happy New Year!