Complex sentence: It declared bankcruptcy on May 11,1931, during the Great Depression but was rescued by the Oesterreichische Nationalbank and the Rothschilds and merged with the "Wiener Bankverein", thus changing its name to "Creditanstalt-Bankverein".
Split into simpler sentences: It declared bankcruptcy on May 11,1931, during the Great Depression. Was rescued by the Oesterreichische Nationalbank and the Rothschilds and merged with the "Wiener Bankverein", thus changing its name to "Creditanstalt-Bankverein".