Surname origin
From Barthorpe Bottoms in the East Riding of Yorkshire. Christopher Barthrup 1706 Register of the Freemen of York.
A Dictionary of English Surnames by P H Reaney. OUP revised third edition 1997. 019860092-5.
However Barthorpe Bottoms is a small hamlet having no church and is joined with Acklam.
Its smallness raises doubts about its use as a surname to identify a person.
The name existed in Essex in the 1300s as Barltripp and it is suggested the name derives from Anglo-Saxon as 'Bera's' or the barley farmer and 'Throp' as an outlying farm with the variants produced by local pronunciations.

Much of the above and this pedigree has been derived from 'The Bar Chart' privately published in 1979 by Roger Barltrop.
The Society of Genealogists in London has a copy.

Reuben BARTRUP (1724 - 1793) married in 1750 Elizabeth TAYLOR ( - 1797) at Great Yeldham.
They had children:-
• William (1751 - 1810) = Jane CLARK ( - 1781)
  • William (1771 - 1827) = Mary HIGGONS (1771-?)
    • William (1796 - )
    • Samuel (1799 - )
    • Sarah (1801 - )
    • Daniel (1804 - )
    • John (1807 - )
    • Mary (1810 - )
    • James (1813 - )
    • Frances (1816 - ) = Edward PARKER
  • Jane (1774 - ) = Jeremiah HARDY
• Reuben (1753 - liv. 1813) = Elizabeth INCH
  • Anne BARTRAM (1784)X
  • Joseph BARTRAM (1786-?)
  • William BARTRAM (1788-?)
  • Reuben (c.1786 - 1869) = Mary PANNELL (c.1791 - 1858)
    • William (1807 - 1883) =  Susan SMEE (1807 - 1885)
      • Jane (c.1829 - ) = William TAYLOR
      • Emma (c.1831 - ) = William SMITH
    • Charlotte (1809 - 1882) = (1) John BUSH (1808 - 1836) = (2)Gabriel BUSH (c.1817- 1901)
    • Hannah (1805 - 1811)
    • Samuel (c.1814 - 1893) = Ellen Butler SAWARD (c.1821 - 1915)
    • Caroline (1816 - 1891) = Robert FINCH (c.1821 - )
    • Daniel (1820 - 1890) = Fanny RUTLAND (c.1818 - 1893)
      • Lydia (1847 - 1928) = Stephen INCE (1848 - 1904)
      • William (1849 - 1909) = Emma ALEFOUNDER (c.1853 - 1923)
      • Eliza (1851 - 1923) = William WEST (1854 - 1913)
        • Annie Elizabeth WEST (1882 - 1961) = Alfred John COX (1885 -1954)
          • Alfred John William COX  =  Irene Mary FITT
      • Henry (1853 - 1899)
      • Charles (1855 - 1925) = Elizabeth Maria WANT (1857 - 1955)
    • Sarah (1823 - 1856)
    • Reuben (1826 - 1880)
    • Elizabeth (1829 - 1891) = Edward HICKFORD (1829 - 1897)
    • Hannah (1834 - living 1851)
• Elizabeth (1756 - ) = Richard PANNELL
• Joseph (1758 - ) = Sarah NEWMAN