Henry IV Plantagenet were married in a religious ceremony on July 27th, 1380 in
Rochford, Essex. He had a biological son named
Thomas Plantagenet of.
Family Notes
When Henry IV married Lady Mary de Bohun, he was only Earl of Derby. He
was not King, nor was he even heir to the throne. His cousin Richard II was king, with the heirs of Philippa of Clarence coming between Henry of Derby and the throne. Therefore it was perfectly acceptable for an Earl to marry Lady Mary de Bohun, considering that she and her sister were joint heiresses to considerable wealth.