paragraph: In Italy, he returned to painting, at first producing a series of works executed in tempera on linen. These include portraits and altarpieces, notably, the Paumgartner altarpiece and the Adoration of the Magi. In early 1506, he returned to Venice and stayed there until the spring of 1507. By this time Durer's engravings had attained great popularity and were being copied. In Venice he was given a valuable commission from the emigrant German community for the church of San Bartolomeo. This was the altar-piece known as the Adoration of the Virgin or the Feast of Rose Garlands. It includes portraits of members of Venice's German community, but shows a strong Italian influence. It was subsequently acquired by the Emperor Rudolf II and taken to Prague. Other paintings Durer produced in Venice include The Virgin and Child with the Goldfinch, Christ Disputing with the Doctors (supposedly produced in a mere five days), and a number of smaller works. 
question: Who acquired the altar-piece known as the Adoration of the Virgin or Feast of Rose Garlands?
answer: Charles V