Richardson supported the overthrow of Mary, Queen of Scots. He attended the coronation of the infant
James VI in 1567, and was present at Mary's defeat at the
battle of Langside in May 1568 on the side of her half-brother and opponent,
James Stuart, 1st Earl of Moray. In 1569 he voted to refuse
Mary, Queen of Scots' divorce from
Bothwell. His support for the new regime is also evidenced by a loan of £5,000
Scots to the Earl of Moray, now the
Regent of Scotland, on 17 September 1567, secured on a pledge of a selection of the queen's jewels. He raised money for Regent Moray by pawning more of the
personal jewellery of Mary, Queen of Scots.
Regent Mar wrote to him to complain about the sale of one of Mary's emerald jewels in Paris. A gold chain belt of pearl knots and a hair garnishing with 57 diamonds was returned to
Holyrood Palace by his son James Richardson on 18 March 1580. In 1570, as he was "greitlie superexpendit as treasurer and unable to pay his creditors" Regent Moray gave him the revenue arising from wards and marriages and vacant benefices. In January 1571 the lease of the mint, which he had held since 1566, was renewed for three years, with half the profits to pay off his superexpenses as treasurer. According to a contemporary source, John
Cunningham of Drumquhassle had been made "half thesaurer, with Mr Robert Ritchartsone that wes thesaurer of befoir" in July 1570, but Richardson remained in sole charge until 24 June 1571, when he was replaced by
William, Lord Ruthven. During the
Marian Civil War, in June 1572, conditions were agreed at Leith between Richardson, as furnisher of the mint or "cunziehous" and
John Acheson to mint silver coins. Richardson retained control of the mint until March 1573, his share of the profits amounting to more than £5400
Scots. Thereafter he continued to receive money from the mint to redeem the royal jewels that had been pledged to him, further payments being made to his sons after his death, which probably took place between May and November 1578. ==Family==