Nelson was born at the Rectory of Burnham Thorpe, Norfolk, East England, UK, the son of the village rector Edmund Nelson and his wife Catherine. He attended schools at Norwich and North Walsham before entering the Royal Navy at Chatham in 1770. Under the patronage of an uncle, Captain Maurice Suckling, his naval experience widened rapidly; first by his attachment to a Caribbean-bound merchant ship, and in 1773 by an arduous expedition to the Arctic. A voyage to India followed, but he had to be invalided home after a near fatal malarial fever which left him with recurrent partial paralysis for the rest of his life, in addition to his incurable sea-sickness.
In 1779 at the age of 20, he became captain of a frigate ship in the West Indies, and during the American War served under Admiral Robert Digby and later Lord Samuel Hood. In 1784 he returned to the West Indies to enforce the Navigation Acts prohibiting direct trade between the new American States and the remaining British colonies. His rigid and direct enforcement of the law soon brought him into conflict with the traders, his commander-in-chief, and the Governor of the Leeward Is. However, their attempts to have Nelson removed or court-martialled rebounded on them following his successful petitions to the Admiralty and King George III.
While on the island of Nevis, Nelson met and, in 1787, married Frances (Fanny) Nisbet (1761-1831), a widow with a son, Josiah. Returning to England, he found himself out of favour both with the Admiralty, which was embarrassed by his zealous execution of duty in the West Indies, and with George III for associating with his disreputable son, Prince William Henry. He was refused another ship, but five years later was recalled at the outbreak of the Revolutionary Wars (1792-1802) with France. In 1794 he was given the task of securing Corsica as a Mediterranean base for the Royal Navy. While in Naples gathering recruits, he met William Harrison who, in his capacity as British minister, helped Nelson. The campaign was a major success but, during the attack on Calvi, he was blinded in the right eye by stone splinters from a parapet struck by an enemy shell. Despite his injury, he returned to duty the following day.
On leaving the Mediterranean, the British fleet encountered a Spanish fleet off Cape St Vincent, and inflicted a decisive defeat (1797). Much of the credit for the success of the heavily outgunned British fleet was due to Nelson's bold and unorthodox tactics, for which he received a knighthood. Later promoted to rear-admiral, he held the blockade of Cadiz before being detached to Santa Cruz in the Canary Islands. His ill-founded mission to capture rumoured Spanish treasure ships failed when all element of surprise was lost. His right arm was shattered by grapeshot, and had to be amputated.
In 1798 he was sent on a reconnaissance mission to locate the French fleet. It was eventually found in Abu Qir (Aboukir) Bay near Alexandria, where he executed a daring attack as night fell. The British fleet inflicted a massive defeat (the Battle of the Nile), leaving Napoleon's army stranded in Egypt. Nelson, who had again been wounded, returned to Naples, there to be nursed by Emma, the wife of Sir William Hamilton. He was raised to the peerage as Baron Nelson of the Nile, and appointed principal military adviser to the Court of Ferdinand IV, King of the Two Sicilies. This period was marked by controversy. His advice to send an army to recapture Rome from the French resulted in a humiliating defeat, while his public affair with Lady Hamilton exposed him to criticism. In 1800 he relinquished his command because of ill health, and escorted the Hamiltons overland to England.
Following his return, estrangement from his wife soon resulted in separation. With Emma pregnant with their daughter Horatia, and faced with difficult financial circumstances, he applied for active service. In 1801 he was promoted to vice-admiral and appointed second-in-command to Admiral Sir Hyde Parker in an expedition to break the 'armed neutrality' of the Baltic States. The fleet sailed for Denmark and, despite the irresolute Parker, engaged the Danish fleet at anchor off Copenhagen. During the course of battle, which inflicted heavy losses on both sides, Nelson ignored Parker's signal to disengage from the fighting by putting his telescope up to his blind eye and claiming that he had seen no such signal. An hour later the battle was won. He was appointed commander-in-chief of the fleet following Parker's recall, and elevated to viscount.
Renewed hostilities with France saw his return to active service as commander-in-chief of the Mediterranean fleet on board the flagship HMS Victory. In this capacity, his questionable tactics in enforcing a loose blockade of the French-held ports, encouraging the enemy to leave the port and fight, allowed a French fleet under Admiral Villeneuve to escape from Toulon (Jan 1805). A futile chase ensued across the Atlantic to the West Indies and back. This was part of Napoleon's plan to decoy the Royal Navy from the Channel in order to allow him to invade England unmolested. However, Napoleon's combined Spanish and French fleet sweeping through the channel to cover for the invasion was devastated by Nelson's eventual engagement of Villeneuve's fleet off Cape Trafalgar (21 Oct 1805). At the height of the battle, and with victory in sight, Nelson was mortally wounded as he paced the quarter-deck with Captain Hardy; he died some three hours later as the battle ended, and his body was brought back to England.He was buried in St Paul's Cathedral, and a column erected to his memory in Trafalgar Square. Despite the adulation he received after his death, Emma was ignored, and died in abject poverty in Calais nine years later. Horatia, however, returned to Norfolk, and married a clergyman.