Complex sentence: Between 1361 and 1384 a group of Augustinian friars created the de Bohun manuscripts at Pleshey Castle; eleven books, one of them a Psalter, celebrating Mary de Bohun's marriage to Henry Bolingbroke, the future Henry IV, King of England.
Split into simpler sentences: Between 1361 and 1384 a group of Augustinian friars created the de Bohun manuscripts at Pleshey Castle. Here they completed eleven books, one of them a Psalter celebrating Mary de Bohun's marriage to Henry Bolingbroke, the future Henry IV, King of England.