Complex sentence: It was initially incorporated in August 1983 in Michigan and in June 2006 Sotheby's Holdings, Inc. reincorporated in the State of Delaware and was renamed Sotheby's.
Split into simpler sentences: It was initially incorporated in August 1983 in Michigan. In June 2006, Sotheby's Holdings, Inc. reincorporated in the State of Delaware and was renamed Sotheby's.