A person of rank, power, influence, or distinction often in a specified area. (Merriam – Webster)
A person who is very rich and successful in business or industry. (Cambridge Dictionary)
A person of great influence, importance, or standing in a particular enterprise, field of business, etc. (Dictionary.com)
A person of eminence or distinction in any field: (Dictionary.com)
A magnate is someone who has earned a lot of money from a particular business or industry. (Collins Dictionary)
Magnates and kings.
The Politics of Magnate Power in England and Wales, 1389-1413.
The Risk Of Being A Shipping Magnate.