Hendrik Maartens Heijkoop ^31,648,738

Hendrik married Jannigje Frederiks Kool, daughter of Frederik Anthonies Kool and Maria Ruths Kool, on 4 november 1820 in Everdingen ⁶⁴⁸.^,738 (Jannigje Frederiks Kool was born on 3 may 1799 in Hagestein ^31,648,738, christened on 19 may 1799 in Everdingen ^31,648 and died on 10 november 1842 in Leerdam ⁶⁴⁸.)

Hendrik also married Metje Gerrits van Zijderveld, daughter of Gerrit Cornelisz van Zijderveld and Grietje Anthonies Kool, on 23 october 1846 in Leerdam.⁶⁴⁸ (Metje Gerrits van Zijderveld was born on 13 october 1798 in Schoonrewoerd ^31,648, christened on 21 october 1798 in Schoonrewoerd ^31,648 and died on 6 august 1865 in Leerdam ⁶⁴⁸.)