the later part of the fifteenth century. Further work was done over the next fifty years by Thomas Spens, William Elphinstone and Gavin Dunbar; Dunbar is responsible for the heraldic ceiling and the two western spires. The chancel was demolished in 1560 during the Scottish Reformation. The bells and lead from the roof were sent to be sold in Holland, but the ship sank near Girdle Ness. The central tower and spire collapsed in 1688, in a storm, and this destroyed the choir and transepts. The west arch of the crossing was then filled in, and worship carried on in the nave only; the current church consists only of the nave and aisles of the earlier building. The ruined transepts and crossing are under the care of Historic Environment Scotland, and contain an important group of late medieval bishops' tombs, protected from the weather by modern canopies. The cathedral is chiefly built of outlayer granite. On the unique flat panelled ceiling of the nave (first half of the 16th century) are the heraldic shields of the contemporary kings of Europe, and the chief earls and bishops of Scotland. The cathedral is an example of a fortified kirk, with twin towers, believed to have been inspired by the central tower of Perth's St John's Kirk, built in the fashion of fourteenth-century tower houses. Their walls have the strength to hold spiral staircases to the upper floors and battlements. The spires which presently crown the towers were added in the 15th century. Bishops Gavin Dunbar and Alexander Galloway built the western towers and installed the heraldic ceiling. Notable figures buried in the cathedral cemetery include the author J.J. Bell, Robert Brough, Gavin Dunbar, Robert Laws, a missionary to Malawi and William Ogilvie of Pittensear—the ‘rebel professor’. St Machar's kirk has been featured by BBC TV's Songs of Praise. Ministry The minister from 2004 to 2011 was the Reverend Dr Alan D. Falconer, who previously worked with the Secretariat of the World Council of Churches in Geneva. In 2011 the Reverend Jane Barron became the first female minister of St Machar's Cathedral. She was formerly minister at St Andrew's Church, Jerusalem and Stobswell Parish Church, Dundee. In 2015 Rev Barry Dunsmore became minister of St Machar's Cathedral. Notable past ministers include: James Lawson first Presbyterian minister 1569 to 1572 – translated to St Giles in Edinburgh to replace John Knox, Moderator in 1580