In February 1560 he was one of the signatories to the Treaty of Berwick, by which Queen Elizabeth I of England agreed to send a force to assist them in driving out the French, and the following April he joined the English army at the Prestonpans.
"[7] Robert Boyd was present at the unsuccessful attack made on Leith on 7 May by the English,[8] and on 10 May signed the document by which the Treaty of Berwick was confirmed.
On 16 August 1560 he signed the address to Elizabeth, praying her to marry the James Hamilton, Earl of Arran,[9] and on 27 January 1561 he subscribed the "Book of Discipline of the Kirk".
[nb 3] He was one of the jury who acquitted Bothwell, 12 April 1567,[15] and 17 May following, two days after the Queen's forced marriage with that nobleman, was made a Privy Councillor.
[20] In September 1568, Boyd was appointed one of Bishop John Lesley' colleagues for the conference to be held at York,[21] and while there is accused of having "practised to steale away" Mary secretly.
[27][nb 4] The Privy Council decided to do nothing,[23] and after reporting the failure of his mission to Mary, Lord Boyd appears to have remained in England for some time, during which the record of his life is very scanty.
[41] Boyd attended the meeting of the nobility at Dunblane on 17 July 1571,[42] and is recorded as having endeavoured to bring all to the Queen's side;[43] but on 12 August he, together with the Earls of Argyll, Oassillis, and Eglinton, Econsidering the calamite quhairwith this realme, thair native cuntre, is plagit", and that the Queen was detained in England, came to an agreement with the Earls of Morton and Mar to serve the King.
[44] The Queen had evidently anticipated something of the kind, as on 28 June she had written to de la Motte Fénelon that she was advised that Argyll, Atholl, and Boyd "comme désespérés d'aucuue ayde commancent à se rettirer et regarder qui aura du meilleur".
[45] On 5 September Lord Boyd was a consenting party to the election of the Earl of Mar as Regent, and two days afterwards he was made a Privy Councillor.
[53] On 2 January 1574 Boyd obtained from Morton charters of the offices of Bailiary and Justiciary of the regality of Glasgow for himself and his heirs,[54] having in the previous November forcibly ejected Sir John Stewart.
[58] On the 23rd of the same month he was compelled to surrender the Bailiary of the Regality of Glasgow to the King, as Earl of Lennox[59] On 8 September he was one of the eight noblemen nominated by the King for quieting the troubles "that be thair gude counsale and assistence sa gude and necessar [sic] a work may proceid and be set fordwart, to the plesour of God, his Hienes obedience and the repose and quietnes of the troublit commounwelth".
[60] The next year, he was, on 1 May 1575, appointed one of the commission to pursue and arrest the Lords John and Claude Hamilton, who were charged with the murders of the Regents Moray and Lennox.
[62] Lord Boyd was a party to the conspiracy known as the Raid of Ruthven,[63] but on its collapse he retired to France, from whence he was recalled by a highly complimentary letter from King James, dated 11 February 1586.
He was back in Scotland before 21 June, when for the third time he was appointed an Extraordinary Lord of Session, and he was one of the three Scottish commissioners who negotiated the treaty of alliance with England, which was signed 5 July.
In 1589 he was placed on the commission to enforce the statute against the Jesuits,[65] and in October, on the King's leaving for Norway, was constituted one of the Wardens of the Marches, with a seat on the Council.
[66] This was his last public appearance, and he died 3 January 1590,[67] aged seventy-two, having for over thirty years played a prominent part in Scottish history.