His mother 's identity is not completely clear but some sources suggest that she was Melusina von der Schulenburg .
Calvert was born in England in around 1730 - 32 , the illegitimate son of Charles Calvert , 5th Baron Baltimore .
Calvert 's mother 's identity is not completely clear but some sources suggest that she was Melusina von der Schulenburg .
Calvert was born in England in around 1730 - 32 , the illegitimate son of Charles Calvert , 5th Baron Baltimore .