My Grandfather's name was Loftus Anster Wattell Fitzgerald and as far back as at least 1800 the name of ANSTER has appeared as either a First name or a Middle name.

Does anyone have any idea where the name could of originated from?
ALSO
I have traced my family as far back as 1800 as being in India, but who was the first Fitzgerald to go to India, remains a mystery!

Harold Fitzgerald appears in 1820 with his wife Eliza as Indigo Planters in Bihar India.
Any info would be very much appreciated

Many thanks