His reign of 72 years and 110 days is the longest of any monarch of a major country in European history. In this age of absolutism in Europe, Louis XIV's France was a leader in the growing centralization of power.
If you omit the GROUP BY clause, then Oracle applies aggregate functions in the select list to all the rows in the queried table or view. You use aggregate functions in the HAVING clause to eliminate groups from the output based on the results of the aggregate functions, rather than on the values of the individual rows of the queried table or view.
Aggregate always returns a data.frame as a result. This data.frame will contain the (now unique) values from the input parameter by as the first column and then columns containing the results of the call to the function in the FUN parameter applied to the parts of the columns of the inputted data.frame.