Alistair Gordon Lethbridge-Stewart

Brigadier[1] Sir Alistair Gordon Lethbridge-Stewart — often called the Brigadier or the Brig — was one of the founders of the United Nations Intelligence Taskforce (later renamed the Unified Intelligence Taskforce). Through his work, he became a trusted ally of the Doctor, as well as a personal friend.

Lethbridge-Stewart had a few extraterrestrial encounters in his early life, but they were all forgotten. A turning point in his life was the Great Intelligence's invasion of London, where he met the Second Doctor and Anne Travers and was inspired to defend Earth from alien threats. Working closely with Travers, Lethbridge-Stewart founded and led the Home-Army Fifth Operational Corps for a short period — during which he was promoted to Brigadier — before becoming the commander of UNIT's UK operations.

Lethbridge-Stewart grew close to the Doctor's third incarnation in the several years they spent together combating alien incursions during the Doctor's exile on Earth. After the Third Doctor's regeneration — which the Brigadier witnessed — the Doctor became more distanced from Alistair and UNIT. After several adventures with later incarnations of the Doctor, the Brigadier retired from UNIT and became a teacher at Brendon Public School.

Lethbridge-Stewart eventually left Brendon and returned to working with UNIT, having many more encounters with the Doctor and extraterrestrial menaces.

By some accounts, the Brigadier died in the early 21st century and was later resurrected as a Cyberman. By other accounts, the Brigadier's body was rejuvenated during the wedding of Bernice Summerfield and Jason Kane in 2010, allowing him to live far into the 21st century and play a pivotal role in the Earth-Avalon war.

Alistair's daughter, Kate Stewart, gave him a continuing legacy, both in her role as UNIT's Chief Scientific Officer and through her interactions with the Doctor. He made sure to that she learned to always trust science to find an answer, rather than rely solely on the military solution like he did.

Alistair Gordon Lethbridge-Stewart came from a long line of soldiers, nearly 400 years worth, who dated back to the Stewarts from Lanark and the Lethbridges in Devon. (PROSE: The Forgotten Son) He was of Scottish descent. (TV: Terror of the Zygons) Both his grandfather and great-uncle were born in Scotland, as was his father. (PROSE: What's Past is Prologue, The Note)

As they approached their respective regenerations, the First Doctor and the Twelfth Doctor met Archibald Hamish Lethbridge-Stewart, a relative of Alistair who was slated to die alongside a German soldier in Ypres on Christmas. The two Doctors promised that they would check up on his family, but the Twelfth Doctor adjusted Archibald's time period slightly so that time resumed for Archibald and his opponent a couple of hours after Archibald left. As a result, the two men's standoff ended with the beginning of the Christmas truce, changing the future slightly so that both men survived. (TV: Twice Upon a Time) Alistair grew up believing Archibald was his great uncle, although it remains unclear whether or not he discovered the truth after 1945; that Archibald was really the father of Gordon Lethbridge-Stewart, and thus Alistair's grandfather. (PROSE: The Note)

Alistair Gordon Lethbridge-Stewart was born on 22 February either 1929 or 1930 (PROSE: Blood Heat, No Future, The Forgotten Son) to Mary and Gordon Conall Lethbridge-Stewart. (PROSE: The Forgotten Son)

According to one account, he was an only child, and was raised in Simla, India. He was sent to an English prep school. According to this source, Alistair's mother died after he left for England. (PROSE: Island of Death)

Another account held that he was born in Cornwall, England with an older brother, James Lethbridge-Stewart. His mother did not die as early according to this account. He was known among friends and family as "Al".

The young Alistair was pressured to live up to the military traditions of the Lethbridge-Stewart family, particularly by his father (who was an officer in the Royal Air Force) (PROSE: The Forgotten Son) and Alistair Lethbridge-Stewart (the man he believed to be his grandfather). (COMIC: The Warkeeper's Crown)

Alistair's brother and his friends created a group known as "the Bledoe Cadets". However, Alistair was not allowed to join as he was considered too young. (PROSE: The Forgotten Son) When he kept following them, they would drop him in cowpats or drench him to make him stop. (PROSE: The Bledoe Cadets and the Bald Man of Pengriffen)