during the english occupation of scotland under the commonwealth, fortresses in the style of the trace italienne were built. these were polygonal in plan with triangular bastions, as at ayr, inverness and leith. twenty smaller forts were built as far away as orkney and stornoway. control of the highlands was secured by strongpoints at inverlocky and inverness. these were built at a massive cost in money and manpower. the citadel at inverness, begun in 1652 and using stone shipped from as far away as aberdeen, had cost £50,0000 when it was still unfinished by 1655. inverlochy had a garrison of 1,000 and from 1654 became the centre for a new administrative region of lochaber, made up of three of the most remote and lawless shires.