Complex sentence: The building of St Pancras church, was agreed in 1816; after a competition involving thirty or so tenders, designs by the local architect William Inwood in collaboration with his son, Henry William Inwood were accepted.
Split into simpler sentences: The building of St Pancras church, was agreed in 1816. After a competition involving thirty or so tenders, designs by the local architect William Inwood, in collaboration with his son Henry William Inwood, were accepted.