I was checking on the vol.IV of Conde de Jaruco for Betancourts and I can see there are very few " Manuel Betancourts".

I must remind you that is it posible that your relative had a " compound name " and the family called him by his second name..and that also, thru the years the names have variations ( some letters added or some taken away....)

I just found this entry and maybe , if this is your relative, some of his descendants will give you the clue needed.

Here:

Don Alonso MANUEL Betancourt y Gonzalez , was Mayor of the Villa de Pto. Principe in 1834.
He was married twice at the Catedral : first time: march 17, 1827 with Dña. Maria de Loreto Cisneros Betancourt.

Second marriage:January 1st., 1839 with Dña. Maria Francisca Cisneros y de la Pera.

From this second marriage the had 4 children:
1.-Manuela
2.-Luisa
3.-Maria de las Mercedes
4.-Gaspar Alonso
( all of them of course, Betancourt Cisneros )

To keep the Betancourt surname ( apellido ) , let`s check at the son: Gaspar Alonso Betancourt Cisneros

Gaspar Alonso Betancourt Cisneros married twice:
First wedding: with Malvina Sanchez Pereira y Loret de Mola, july 2nd., 1858.

Second wedding: with Dña. Josefa del Castillo Cisneros on november 26, 1860.

At this point here is not more information on this branch.

. BRANCH TWO ends HERE.

If they had children , we need to look for: Betancourt Castillo and Betancourt Sanchez and I can`t find those surnames in vol. IV.

Does this last names ring a bell ?


As you can see, it doesn`t tell us when Alonso MANUEL Betancourt Gonzalez was born...but following the trail to wedding dates, there is a posssibility that he was born like you said, in 1805, getting married at 22 yeras of age and at 24 again.
And was Mayor at 29 ?

If I find more information, I will post it!
I hope this is the right track to your roots.
Regards, Maruca