Lee Falk had the 3rd Phantom marrying two women Rosamunda (niece of William Shakespeare) and Pura daughter of a maharajah in India. Pura has been down as marrying the 3rd, 4th and 11th Phantoms. The last story Lee Falk wrote about Pura has it featuring as the third. The problem however is that the third also married Rosamunda.
Team Fantomen has made it all make sense by having Rosamunda dying after childbirth and then the Phantom married Pura.
Rosamunda is the mother of the 4th Phantom and died before the 3rd swore the oath. In fact her death pushed the Phantom into his role and it was his lost that helped him understand the 1st decision to dedicate his life to fighting cruelty and injustice.