St Runns Church stands on the site of an early medieval keeill or chapel and its associated burial ground, thought to have been in use during the period circa AD500 to AD1000.  The church is thought to be dedicated to St Runan of Lismore Mochuda. 


A lintel grave has been found extending northeastwards across the road. Early cross-slabs (Manx Crosses Nos. 50 & 81) have been found here. They are said to be early, certainly pre-Viking.


The Old Church, Marown was visited by an Natural History & Antiquarian Society excursion in September 1912. The leader of the party, the Rev A.E. Clarke (vicar of Marown) 'pointed out the former extension at the East end, and gave an account of the excavations made there a few years ago, when, among other things, a fine cross-slab was brought to light, to judge from the carving it might be the work of the eighth century'.