Portable Altar, c. 1200-1220. Germany, Cologne, Gothic Period, 13th century. Walrus ivory, gilded copper, porphyry, champlevé enamel, wood core; overall: 13.1 x 26.9 x 16.9 cm (5 3/16 x 10 9/16 x 6 5/8 in.). The principal decoration of this portable altar is carved of walrus ivory. On the long sides are traditional figures of standing apostles. On the short sides are the seated Virgin with the Magi, and Christ the Judge between the symbols of the Evangelists. The commercial ties between the Rhineland and the Norse peninsula made walrus ivory easily available to the city of Cologne, one of the most important artistic centers in medieval Germany.