Had to look it up, but I think the book your looking for is Master of the Five Magics.
Alodar is the aprrentice, the queen is Vendora, the girl he finally marries is Ariel, the advisor to the queen. Basil steals his potion and uses it to amass the vast wealth for himself.
Alodar is the aprrentice, the queen is Vendora, the girl he finally marries is Ariel, the advisor to the queen. Basil steals his potion and uses it to amass the vast wealth for himself.