John Murray, 4th Earl of Dunmore

Dunmore became royal governor of the Colony of Virginia on 25 September 1771. Despite growing issues with Great Britain, his predecessor, Lord Botetourt, had been a popular governor in Virginia, even though he served only two years before his death. As Virginia's colonial governor, Dunmore directed a series of campaigns against the Indians known as Lord Dunmore's War. The Shawnee were the main target of these attacks, and his avowed purpose was to strengthen Virginia's claims in the west, particularly in the Ohio Country, but as a byproduct it was known he would increase his own power base. Some even accused Dunmore of colluding with the Shawnees and arranging the war to deplete the Virginia militia and help safeguard the Loyalist cause, should there be a colonial rebellion. Dunmore, in his history of the Indian Wars, denied these accusations.[4]

Lacking in diplomatic skills, Dunmore tried to govern without consulting the House of Burgesses of the Colonial Assembly for more than a year, which exacerbated an already tense situation.[5]

When Dunmore finally convened the Colonial Assembly in March 1773, which was the only way he could deal with fiscal issues to financially support his war through additional taxation, the burgesses instead first resolved to form a committee of correspondence to communicate their continued concerns about the Townshend Acts and Gaspee Affair to Great Britain. Dunmore immediately postponed the Assembly. Many of burgesses gathered a short distance away at the Raleigh Tavern and continued discussing their problems with the new taxes, perceived corruption and lack of representation in England. When Dunmore reconvened the Assembly in 1774, the burgesses passed a resolution declaring 1 June 1774 a day of fasting and prayer in Virginia. In response, Dunmore dissolved the House.

The burgesses again reconvened as the Second Virginia Convention and elected delegates to the Continental Congress. Dunmore issued a proclamation against electing delegates to the Congress, but failed to take serious action.[6] In March 1775, Patrick Henry's "Give me Liberty, or give me Death!" speech delivered at St. John's Episcopal Church in Richmond helped convince delegates to approve a resolution calling for armed resistance.[7]

In the face of rising unrest in the colony, Dunmore sought to deprive Virginia's militia of military supplies. Dunmore gave the key to the Williamsburg magazine to Lieutenant Henry Colins, commander of HMS Magdalen, and ordered him to remove the powder, provoking what became known as the Gunpowder Incident. On the night of 20 April 1775, royal marines loaded fifteen half-barrels of powder into the governor's wagon, intent on transporting it down the Quarterpath Road to the James River and the British warship. Local militia rallied, and word of the incident spread across the colony.

The Hanover militia, led by Patrick Henry, arrived outside of Williamsburg on 3 May. That same day, Dunmore evacuated his family from the Governor's Palace to his hunting lodge, Porto Bello in nearby York County.[8] On 6 May, Dunmore issued a proclamation against "a certain Patrick Henry... and a Number of deluded Followers" who had organised "an Independent Company... and put themselves in a Posture of War."[7]

Dunmore threatened to impose martial law, and eventually retreated to Porto Bello to join his family. Dislodged by the Virginia rebels and wounded in the leg,[9] on 8 June, Dunmore took refuge on the British warship HMS Fowey in the York River. Over the next months, Dunmore sent many raiding parties to plunder plantations along the James, York and Potomac rivers, particularly those owned by rebels. The raiders exacerbated tensions, since they not only stole supplies, they also encouraged slaves to rebel. In December, Washington commented "I do not think that forcing his lordship on shipboard is sufficient. Nothing less than depriving him of life or liberty will secure peace to Virginia, as motives of resentment actuate his conduct to a degree equal to the total destruction of that colony."[9]

Dunmore is noted for Dunmore's Proclamation, also known as Lord Dunmore's Offer of Emancipation. Dated 7 November 1775, but proclaimed a week later, Dunmore thereby formally offered freedom to slaves who abandoned their Patriot masters to join the British. Dunmore had previously withheld his signature from a bill against the slave trade.[5] The proclamation appeared to respond to the legislature's proclamation that Dunmore had resigned his position by boarding a warship off Yorktown nearly six months earlier. However, by the end of the war, an estimated 800 to 2000 escaped slaves sought refuge with the British; some served in the army, though the majority served in noncombatant roles.[10][11]

Dunmore organized these Black Loyalists into his Ethiopian Regiment. However, despite winning the Battle of Kemp's Landing on 17 November 1775, Dunmore lost decisively at the Battle of Great Bridge on 9 December 1775. Following that defeat, Dunmore loaded his troops, and many Virginia Loyalists, onto British ships. Smallpox spread in the confined quarters, and some 500 of the 800 members of the Ethiopian Regiment died.[12]

On New Year's Day in 1776, Dunmore gave orders to burn waterfront buildings in Norfolk from which patriot troops were firing on his ships. However, the fire spread. The city burned, and with it any hope that Dunmore's loyalists could return to Virginia.[13] Dunmore retreated to New York. Some ships of his refugee fleet were sent south, mostly to Florida.[14] When he realized he could not regain control in Virginia, Dunmore returned to Britain in July 1776. Dunmore continued to draw his pay as the colony's governor until 1783, when Britain recognized American independence.

From 1787 to 1796, Dunmore served as governor of the Bahamas. During his tenure as governor, the British issued land grants to American Loyalists who went into exile. The sparse population of the Bahamas tripled within a few years. The Loyalists developed cotton as a commodity crop, but it dwindled from insect damage and soil exhaustion. In addition to slaves they brought with them, the loyalist planters' descendants imported more African slaves for labour.