Hi David,

Thank you for contacting Mearto with your appraisal inquiry.
The construction details of the back suggest to me that this canvas is housed in a 19th Century pine stretcher in a 20th Century frame. I am 99% certain that this portrait is a later copy of the portrait in the Prado; I should note that the museum has not identified the artist/author of their portrait of Colonel Francisco Verdugo (1590 - 1600. Oil on canvas, 54 x 37 cm).
I've tried to make out the signature but have not had any luck; an identification may be possible through more in-depth analysis than is within the scope of this appraisal.

Based on the photos and information provided, and subject to examination, this is:

Spanish School, 19th Century
Portrait of Colonel Francisco Verdugo (copy of example in the Prado)
oil on canvas
indistinctly signed center right; verso inscribed lower left "XVI" or "YVI"
100 by 85mm
CONDITION: This painting appears to be in good condition. Probably in its original stretcher, now in a modern frame.
PROVENANCE: Inherited
€ 500-800*
*represents a fair-market value for auction purposes; retail or asking price may vary.

Please let us know if you have additional items to appraise, or questions/concerns, and thank you again for using Mearto.
~ Delia