Seagers of Calne and Hilmarton

[antiqueone]

I have two branches of my tree which include Seagers.

John Seager died about 1718 in Hilmarton. I only have his will and can find nothing else about him, other than a list of his children. One of his daughters Elizabeth married Edward Crook and from her MI at Tytherton Lucas she died 29 may 1767 and was buried 1 June 1767 aged 78.

Another John Seager married Jane Hill 16 Feb 1737 in Bishops Cannings and was buried in Calne 8 Feb 1774. His children were baptised in Calne between 1738 and 1747.

Has anyone any idea on the birth of these two Johns?

I see many references to individuals called Seager alias Parsons from mid 16th century right through to mid 18th century. Has anyone any idea why they had this alias and kept it up for 200 years?