Welser is the surname of an important German banking and merchant family, originally from Augsburg. Along with the Fugger family, the Welser family controlled various sectors of the European economy, and accumulated enormous wealth through trade and the German colonization of the Americas.

The history of the family can be traced back to the 13th century. Later its members became widely known as prominent merchants. In the 15th and 16th centuries, branches of the family settled at Nuremberg and in Austria, respectively.

Bartholomäus Welser lent the Emperor Charles V a great sum of money for which in 1528 he received as security the Province of Venezuela, but in consequence of their rapacious acts the Welsers were deprived of their rule before the Emperor's reign was over. Bartholomäus's niece, Philippine (1527-80), daughter of Franz Welser, renowned for her learning and beauty, secretly married the Archduke Ferdinand, second son of the Emperor Ferdinand I. Her children were debarred from inheriting their father's rank, but one of them became a cardinal and the other distinguished himself as a soldier and was created Margrave of Burgau. Another member of the Welser family, Markus (1558-1614), became famous for his learning.

Gustav Mahler (German pronunciation: [ˈɡʊstaf ˈmaːlɐ]; 7 July 1860 – 18 May 1911) was a late-Romantic Austrian composer and one of the leading conductors of his generation. He was born in the village of Kalischt, Bohemia, in what was then the Austrian Empire, now Kaliště in the Czech Republic. Then his family moved to nearby Iglau (now Jihlava) where Mahler grew up.

As a composer, he acted as a bridge between the 19th century Austro-German tradition and the modernism of the early 20th century. While in his lifetime his status as a conductor was established beyond question, his own music gained wide popularity only after periods of relative neglect which included a ban on its performance in much of Europe during the Nazi era. After 1945 the music was discovered and championed by a new generation of listeners; Mahler then became one of the most frequently performed and recorded of all composers, a position he has sustained into the 21st century.

Born in humble circumstances, Mahler displayed his musical gifts at an early age. After graduating from the Vienna Conservatory in 1878, he held a succession of conducting posts of rising importance in the opera houses of Europe, culminating in his appointment in 1897 as director of the Vienna Court Opera (Hofoper). During his ten years in Vienna, Mahler—who had converted to Catholicism from Judaism to secure the post—experienced regular opposition and hostility from the anti-Semitic press. Nevertheless, his innovative productions and insistence on the highest performance standards ensured his reputation as one of the greatest of opera conductors, particularly as an interpreter of the stage works of Wagner and Mozart. Late in his life he was briefly director of New York's Metropolitan Opera and the New York Philharmonic.