Notes:

He likely had many more children that simply haven't been found in the records yet. He was named in his grandfather's will dated 1657/8 as the son of William. Grandfather William also had another grandson named Marmaduke, son of Marmaduke. After an exhaustive search, we now know that all the Marmaduke's in this family descend from Marmaduke and Marie Somner in Somerset, England except possibly the Marmaduke who descended from Walter's line. The YDNA for that line does not match this line, but the autosomal DNA does suggesting that even Walter Coate's line is tied in probably through one of the female Coate's instead with her son having an illegitimate birth. That would explain all the DNA evidence.

Marmaduke married Elizabeth. Elizabeth was born before 1645; died in in Of Curry Rivel Parish, Somerset, England; was buried on 25 Jan 1702 in North Petherton, Somerset, England. [Group Sheet] [Family Chart]

Notes:

She is listed as the wife of Marmaduke in her burial record meaning that he was still living at the time.