This marvelous altarpiece was done by Tilman Riemenschneider, a German sculptor and woodcarver, one of the most important from the period between late Gothic and early Renaissance. He was active from around 1483 mostly in and around Würzburg. Very popular in his time, Tilman was quite sought for and rich : he had several houses and a vineyard ;) Not only that - the city of Würzburg made him first one of the councilman and then even a Mayor. This all ended in 1525 during the German Peasants’ War : being on a “wrong” side all Würzburg officials were tortured for couple of months, and then stripped of their property. It is said that during this Tilman’s hands were broken, which ended his career.
For those interested I strongly recommend Andrew Graham Dixon’s The Art of Germany : BBC The Art of Germany Ep. 1 - A Divided Land
Holy Blood Altar by Tilman Riemenschneider in Rothenburg, photos from Wikipedia