Which Calvert would be considered a "family head?" (Maryland descendants)

Is there a reason that it can't be both?

Which 2????

http://mdroots.thinkport.org/library/leonardcalvert.asp
http://mdroots.thinkport.org/library/philipcalvert.asp
At first I was thinking Philip and Cecil. But then I reread it and Cecil sent Leonard. So now I'm thinking Philip and Leonard. Were there other Calvert brothers that came to Maryland?

I don't know - the Calvert tree is new to me.

New to me, too. I haven't run into that part of the tree yet....
Perhaps wait until you, or someone else, studies it further.

Generally, it would be whoever was senior and/or had the most land and/or the highest title.

Cecilius, Leonard and Philip all had something major to do with the foundation of Maryland, but only the latter two were actually hands-on -and Philip was doubly junior, being a younger son by a second wife.

There's quite a bit about the Calverts on Wikipedia, starting with their father, George http://en.wikipedia.org/wiki/George_Calvert,_1st_Baron_Baltimore , who planned the whole Maryland enterprise but did not live quite long enough to get it actually started.

http://en.wikipedia.org/wiki/C%C3%A6cilius_Calvert,_2nd_Baron_Balti...
http://en.wikipedia.org/wiki/Leonard_Calvert
http://en.wikipedia.org/wiki/Phillip_Calvert_%28governor%29

And let's not forget:
http://en.wikipedia.org/wiki/Anne_Arundell

Annie got her own county! :)

I was thinking about which Calvert settled into the Colony & their children married into the surrounding families to list as "the family head" genealogically. That's probably the youngest son of the youngest son ...

It's not so simple in this case, because the Calverts kept commuting back and forth across the Atlantic depending on circumstances.

There's a family tree at this link: http://www.lib.umd.edu/binaries/content/assets/public/special/proje... but I'm not sure how complete it is.

Seems the ones who really settled into the Colony were the ones who had no chance of advancement in England, i.e. were illegitimate. Benedict Swingate Calvert was the illegitimate son of the Fifth Lord Baltimore, possibly by the daughter of one of King George I's mistresses, and his wife and cousin, Elizabeth Calvert, was the daughter of the illegitimate son of the 3rd Lord Baltimore.

Between them they had thirteen children, of whom the third, Eleanor Calvert, married John Parke Custis....