The lighthouse and adjacent keepers' cottages were built in 1898 by the John Miller company of Tynemouth, using 645 blocks of stone and 750,000 bricks. It was built on the site of an 11th-century monastic chapel, whose monks maintained a lantern on the tower to warn passing ships of the danger of the rocks. A first-order 'bi-valve' rotating optic was installed by Barbier & Bénard of Paris, very similar to the one they had provided the previous year for Lundy North Lighthouse; it displayed a group-flashing characteristic, flashing twice every 20 seconds. The lamp was powered by paraffin, and was not electrified until 1977; St Mary's was by then the last Trinity House lighthouse lit by oil. As part of the electrification process the fine first-order fresnel lens was removed by Trinity House. Its place in the tower was taken by a four-tier revolving sealed beam lamp array, manufactured by Pharos Marine; it was powered by two 12-volt batteries, charged from the mains electricity supply.
Decommissioning
The lighthouse was decommissioned in 1984. The revolving sealed beam array was reused two years later on the Inner Dowsing light platform in the North Sea, as part of its conversion to become 'the first major lighthouse to be run using solar power'. A few years later, St Mary's was opened as a visitor attraction by the local council. In place of the original optic, Trinity House offered a smaller one from their decommissioned lighthouse at Withernsea, and this can still be seen at the top of the tower. Following closure of the Penzancelighthouse museum, the original lens was returned to St Mary's in 2011 to be put on display.
The lighthouse today
Since 2012 St Mary's lighthouse has been grade II listed. While it no longer functions as a working lighthouse, it is easily accessible and regularly open to visitors; in addition to the lighthouse itself there is a small museum, a visitor's centre, and a café. The cottage was upgraded with a wood pellet boiler in 2014. In 2017 a renovation plan for the site was rejected by the local planning authority due to environmental concerns. A new refurbishment proposal was presented in 2018; however the Heritage Lottery Fund later turned down North Tyneside Council's £2.1m funding application. Another Victorian lighthouse may be found a few miles to the south of the River Tyne. Souter Lighthouse is also now decommissioned, and open to visitors. Souter Lighthouse can be seen with the naked eyefrom the top of St Mary's Lighthouse.
