Complex sentence: According to the genealogies in the "Prieuré" documents his sister married on Jean des Plantard and also state that Guillaume was inducted into the Order of the Ship and the Double Crescent in 1269.
Split into simpler sentences: According to the genealogies in the "Prieuré" documents his sister married one Jean des Plantard. They also state that Guillaume was inducted into the Order of the Ship and the Double Crescent in 1269.