TSQL - Get the greater of two given dates

ALTER function [dbo].[getGreatestDate](

       @date1 date

       , @date2 date

)

returns date

as

begin

       return(

              case when isnull(@date1,'1/1/1900') >= isnull(@date2,'1/1/1900') then @date1 else @date2 end

       );

end

;

 g