In 1570 MacGill reluctantly accepted appointment as Provost of Edinburgh. In November 1571, during the War between Leith and Edinburgh when Mary's supporters held Edinburgh Castle, MacGill was sent with Robert Pitcairn, Commander of Dunfermline to negotiate with Henry, Lord Hunsdon at Berwick upon Tweed. MacGill was to ask for 8 cannons, 3000 footmen and pikemen, and support for 1000 Scots troops, in the cause of the "maintenance and protection of the true religion to the confusion of those that now goes about to disturb the same". MacGill had a particular interest in the siege as the "registers and records of the chief matters" were guarded by artillery at Edinburgh Castle, together with the Scottish Crown jewels. The forces holding Edinburgh Castle, known as the Castilians, in 1572 twice destroyed MacGill's stronghouses in Edinburgh, and while the siege lasted the Burgh Council met in exile at Leith. Regent Morton wrote to MacGill in 1575 asking him to re-negotiate a gold and silver mining contract with the Dutch engineer Cornelius de Vos. A portrait painter working in Scotland at this time, Arnold Bronckorst, was associated with Cornelius and Nicholas Hilliard. Morton also obtained passports for MacGill's sons, John and David, to travel to France to continue their studies. MacGill died on 16 October 1579. Alexander Hay succeeded him as Lord Clerk Register. His executors were his wife Janet Adamsoun and son, Master James Adamson.
Question: Who was asked to renegotiate mining contracts with Cornelius de Vos?
Answer: MacGill; MacGill; MacGill