I think you will find the have been called The Rangers since 1899.
This article details the ownership of the Scottish football club Rangers. Rangers became a limited company in 1899 and was incorporated as The Rangers Football Club Ltd. In the year 2000, Sir David Murray decided to float the club on the stock market, subsequently changing the company into a plc. In 2012, The Rangers Football Club plc entered administration and the company´s business, history and assets were bought by Sevco Scotland Ltd. Sevco Scotland Ltd later changed its name to The Rangers Football Club Ltd.
http://en.m.wikipedia.org/wiki/Ownership_of_Rangers_F.C.