Complex sentence: The construction of St Pancras was largely financed from the estate of L'Abbe Louis Simon; a French émigré priest who came to Ipswich in 1793, during the French Revolution and who was was the first Catholic priest to celebrate Mass regularly in Ipswich since the Reformation.
Split into simpler sentences: The construction of St Pancras was largely financed from the estate of L'Abbe Louis Simon; a French émigré priest who came to Ipswich in 1793, during the French Revolution. Abbe Simon was the first Catholic priest to celebrate Mass regularly in Ipswich since the Reformation.