The Battle of the River Plate, 1939.
France
The British victory in capturing the seaport of Charleston, South Carolina, in May 1780 was a significant strategic achievement during the American Revolutionary War. Charleston was a vital port for the Continental Army, and its fall provided the British with a major supply base and control over the southern colonies. This victory also allowed the British to strengthen their military presence in the South and undermined American morale. It marked one of the largest American surrenders of the war, with thousands of troops taken prisoner.
Tennessee
Coldharbour in the Virginia theatre, or Kennesaw in the Western theatre, if you classify that as a major victory.
Tennessee
The southernmost site of a British victory is the Battle of South Georgia, which took place in 1982 during the Falklands War. British forces successfully reclaimed the island from Argentine occupation, marking a significant military achievement. This victory was crucial in the context of the broader conflict over the Falkland Islands. South Georgia is located roughly 54 degrees south latitude, making it the southernmost site of British military success.
The British Army's first major victory during the Napoleonic Wars was the Battle of Trafalgar, fought on October 21, 1805. In this naval engagement, Admiral Horatio Nelson led the British fleet to a decisive victory against the combined French and Spanish fleets. The battle secured British naval dominance and effectively ended Napoleon's plans to invade Britain. Nelson's tactics and leadership were pivotal in achieving this significant victory.
The first major target in the South for the British during the Revolutionary War was Charleston, South Carolina. Capturing Charleston was strategic for the British as it was a key port city and a center of trade and loyalty in the South. The British aimed to gain control over the southern colonies and exploit Loyalist support, believing that they could rally more loyalists to their cause in this region. The successful siege of Charleston in 1780 marked a significant early victory for the British in the Southern campaign.
During the American Civil War, the South gained confidence with each major victory that occurred, particularly from 1861 to 1863. Of special significance for Southern confidence was the South's victory in the first major battle of the war, the First Battle of Bull Run in July 1861.
The colony of South Carolina was "owned" by the British - before the Revolutionary War ended in victory for the U.S. in 1981.
I think First Bull Run might be classified as a major victory for the Confederates. Otherwise, we're probably talking about Lee's Seven Days Battles in Summer 1862.
If you refer to 1910 british victory against afrikaners (permanent settlers in south Africa of dutch origins), than it's south Africa.