The territory continued to attract new settlers, primarily from Virginia ; and by 1666, the territory had met the requirements to become established as a county in the province with its own local government.

In October 1666, Ashley met John Locke, who would in time become his personal secretary.

He chose a small group of scholars who met on 22 December 1666 in the King's library, and thereafter held twice-weekly working meetings there.

When the Paris Academy of Sciences met for the first time in 1666, a commemorative medal was struck portraying Minerva on its reverse, surrounded by symbols of astronomy, anatomy, and chemistry.

The fleets, now much more equal in quality, met again at the Four Days Battle in June 1666.

* Shivaji came to Agra in 1666 as per the " Purandar Treaty " entered into with Mirza Raje Jaisingh to met Aurangzeb in the Diwan-i-Khas.

The Huygens-Sybilla letters indicate that in 1665 Froberger travelled to Mainz, where he performed at the court of the Elector-Archbishop of Mainz and met Huygens in person for the first time ; and at a certain point in 1666 the composer had plans to return to the imperial court in Vienna.

Notable English autobiographies of the 17th century include those of Lord Herbert of Cherbury ( 1643, published 1764 ) and John Bunyan ( Grace Abounding to the Chief of Sinners, 1666 ).

On August 22, 1666, Lord Baltimore issued a proclamation establishing the new county, including the establishment of a complete civil and military organization.

The Red Velvet Room once contained the largest and most expensive paintings in Lord Burlington's collection, including paintings by Sir Anthony van Dyck ( 1599 – 1641 ), Giacomo Cavedone ( 1577 – 1660 ), Peter Paul Rubens ( 1573 – 1640 ), Rembrandt van Ryn ( 1606 – 69 ), Salvator Rosa ( 1615 – 1673 ), Pier Francesco Mola ( 1612 – 1666 ), Jacopo Ligozzi ( c. 1547 – 1632 ), Jean Lemaire ( 1598 – 1659 ), Francisque Millet ( 1642 – 79 ) and Leonardo da Vinci ( 1452 – 1519 ).

Another notable local noble was Sir Thomas Bloodworth of nearby Thorncroft Manor, who was Lord Mayor of London during the Great Fire of London in 1666.

* Sir Thomas Bloodworth ( 1620 – 1682 ), Lord Mayor of London during the Great Fire of 1666, owned and lived at nearby Thorncroft Manor.

* Sir Daniel Bellingham ( 1665 – 1666 ), First Lord Mayor

* Jean Desmynieres ( 1666 – 67 ) and Lewis Desmynieres ( 1669 – 70 ), Huguenot Lord Mayors of Dublin

King Charles II created him Earl of Burlington on 20 March 1664, and on 13 March 1666, he was appointed Lord Lieutenant of Yorkshire.

He was appointed head of Kronobergs regemente in 1637, Major General in 1643, Privy Councilor in 1652, Field Marshal in 1656, under the terms of the Treaty of Roskilde in 1658 became Governor General of Scania, Halland and Blekinge, Lord High Admiral in 1664, and Chancellor of Lund University in 1666.

* The Earl of Clarendon, Lord Chancellor, at the trial of The Lord Morley, 1666

The fire was the biggest conflagration seen in London since the Great Fire of 1666, and an enormous crowd flocked to Westminster to witness the spectacle, including Lord Melbourne, the prime minister, and many of his cabinet.

* Thomas Butler, 6th Earl of Ossory ( Made Lord Butler of Moore Park in 1666 )

* created an English peer as Lord Butler ( in 1666 ).

The 5th Lord Ogilvy's grandson, James Ogilvy ( c. 1593 – 1666 ), was created Earl of Airlie by Charles I. at York in 1639.

* Hugh Fraser, 9th Lord Lovat ( 1666 – 1696 )

* Alexander Colville, 5th Lord Colville of Culross ( 1666 – 1717 )

Although meeting at Gresham College, the Society temporarily relocated to Arundel House in 1666 after the Great Fire of London, which did not harm Gresham but did lead to its appropriation by the Lord Mayor.

** Robert Spencer, Lord Spencer ( 1666 – 1688 )

Robert Bertie, 1st Duke of Ancaster and Kesteven PC ( 20 October 1660 – 26 July 1723 ), styled Lord Willoughby de Eresby between 1666 and 1701 and known as The Earl of Lindsey between 1701 and 1706 and as The Marquess of Lindsey between 1706 and 1715, was a British statesman and nobleman.

He came of an old family settled in Ireland since the days of Sir Faithful Fortescue ( 1581 – 1666 ), whose uncle, Arthur Chichester, 1st Baron Chichester, was Lord Deputy.

In 1666 Kirke obtained his first commission in the Lord Admiral's regiment, and subsequently served in the Blues.

Sir Anthony died in about 1666 and is entombed under the floor of the round tower of the Temple Church in the Inner Temple in London.

It was also the birthplace of Isaac Jackson, son of Anthony Jackson III ( who some say was a yeoman son in turn of the Charles II courtier, Sir Anthomy Jackson II, of Killingswold Grove, East Yorkshire, England ) of Eccleston, Lancashire, England who died in nearby County Cavan after 1666.

* Anthony Eusebius ( 1666 – 1692 )

After their father's death in 1666, Rudolph Augustus, Anthony Ulrich's elder brother, became reigning duke and made Anthony Ulrich his proxy.

* 1666 – George Hamilton, 1st Earl of Orkney, British soldier ( d. 1737 )

* 1737 – George Hamilton, 1st Earl of Orkney, British soldier ( b. 1666 )

* January 29 – George Hamilton, 1st Earl of Orkney, British soldier ( b. 1666 )

# Lady Mary Rich ( born c. 1636 – 8 February 1666 ), married John Campbell, 1st Earl of Breadalbane and Holland.

* John Holles, 2nd Earl of Clare ( 1595 – 1666 ), eldest son of the 1st Earl

* David Boyle, 1st Earl of Glasgow ( 1666 – 1733 ), Scottish politician

* Mountjoy Blount, 1st Earl of Newport ( 1597 – 1666 )

* George Feilding, 1st Earl of Desmond ( d. 1666 )

* George Granville, 1st Baron Lansdowne, " 1st Duke of Albemarle " ( 1666 – 1735 ), a notable Tory, was made a Jacobite peer by " James III "

* David Boyle, 1st Earl of Glasgow ( 1666 – 1733 )

* George Hamilton, 1st Earl of Orkney ( 1666 – 1737 )

Thomas Parker, 1st Earl of Macclesfield PC, FRS ( 23 July 1666 – 28 April 1732 ) was an English Whig politician.

* Sir John Chetwode, 1st Baronet ( 1666 – 1733 ).

* Thomas Parker, 1st Earl of Macclesfield ( 1666 – 1732 ), English Whig politician

* Henry Carey, 1st Earl of Dover, 4th Baron Hunsdon ( d. 1666 )

* Sir Richard Fanshawe, 1st Baronet ( 1608 – 1666 ), English diplomat to Portugal and Spain

* Sir William Brownlow, 1st Baronet ( c. 1595 – 1666 ), English politician and barrister

* Sir Nicholas Bacon, 1st Baronet, of Gillingham ( 1623 – 1666 )

Edward Montagu, 1st Earl of Sandwich, 1625 – 1672 by Sir Peter Lely, painted 1666

Sir Edward Montagu, 1st Earl of Sandwich, 1625 – 1672 by Sir Peter Lely, painted 1666, part of the Flagmen of Lowestoft series.

* George Granville, 1st Baron Lansdowne ( 1666 – 1735 ) created baron in 1712,

Sir Richard Fanshawe, 1st Baronet ( June 1608 – 16 June 1666 ) was an English poet and translator.