Two thirteenth-century decisions, more than anything else, made Lincoln's Inn possible. A papal bull in 1218 banned the clergy from teaching common law, and on 2 December 1234 Henry III decreed that no institution of legal education could exist within the City of London. The lawyers — newly secular, newly homeless — drifted west to the hamlet of Holborn, just outside the City walls and conveniently close to the courts at Westminster Hall. Henry de Lacy, the 3rd Earl of Lincoln, encouraged them to settle on land he controlled. After his death in 1310, the lawyers who clustered there became known by his name. The earliest entries in the Black Books, dated 1422, already show an organised disciplined society — meaning the Inn must have coalesced sometime in the long decades between de Lacy's death and that first surviving page.

The oldest surviving piece of Lincoln's Inn is the Gatehouse on Chancery Lane, built between 1518 and 1521. The Treasurer of the day, Sir Thomas Lovell, paid at least a third of the cost out of his own pocket and personally supervised construction — which is why his arms still hang on it, alongside those of Henry VIII and the Earl of Lincoln. The oak gates date from 1564. A few steps inside the wall sits the chapel, built between 1620 and 1623 to a design by Inigo Jones, the architect who imported the Italian Renaissance into English building. The chapel rises on a fan-vaulted undercroft that has served, sometimes simultaneously, as crypt, meeting place, and a sheltered spot to walk in the rain. John Donne preached here as the Inn's chaplain between 1616 and 1622, in the years when he was already famous as the metaphysical poet but had not yet become Dean of St Paul's. The chapel bell, which may or may not date from 1596, traditionally chimed a 9 pm curfew — one stroke for each year of the current Treasurer's age.

The Black Books reward patient reading. In 1478 one John Glynne was expelled from the Society for using "presumptious and unsuitable words" in front of the governors. In 1505 the rules had to specifically forbid a Master from being found in Clerks' Commons unless he was studying a point of law there — meaning Masters were sneaking down to dine more cheaply with the clerks. By 1466 the Inn already distinguished between barristers "at the Bar" and those "not at the Bar," the seed of a profession-wide vocabulary. The Inn would not admit a female member until 1920, when Marjorie Powell was called. In 1943, when Queen Mary was elected Royal Bencher, she became the first female Bencher in any Inn of Court. Today the Inn elects honorary Benchers from outside the law — Margaret Thatcher held that status — and a Royal Bencher, currently the Duke of Kent.

Lincoln's Inn does not merely produce barristers; it has produced governments. William Pitt the Younger and H. H. Asquith and Tony Blair were members. So was William Ewart Gladstone. So, on a different continent, was Muhammad Ali Jinnah, who studied here in 1876 and would later become the founder and first Governor-General of Pakistan. Sir Muhammad Iqbal, regarded as Pakistan's national poet, joined the year after Jinnah. Margaret Thatcher specialised in taxation law before politics consumed her. Zulfiqar Ali Bhutto, Shankar Dayal Sharma, Chaim Herzog, Sultan Azlan Shah of Perak — the roll call reads like an atlas of post-imperial leadership. Gnanendramohan Tagore, called here in 1862, was the first Asian to be called to the English Bar. The brick walls have outlasted empires the lawyers helped build and dismantle.

The Library contains roughly 150,000 volumes, including the Hale Manuscripts left to the Inn by the jurist Sir Matthew Hale on his death in 1676, plus over a thousand rare manuscripts and a complete set of Parliamentary records. Queen Victoria opened it in 1845, along with the 120-foot Great Hall used for calls to the Bar and concerts arranged by the Bar Musical Society. The buildings of New Square, finished around 1697, are still partly freehold — individual owners holding particular floors — a quirk left over from a seventeenth-century compromise between the Inn and a man named Henry Serle. Behind the Great Hall, under its broad east terrace, sits the Ashworth Centre, an underground 150-seat lecture theatre opened by Queen Elizabeth II in December 2018, named after Mercy Ashworth, one of the first women called to the Bar by Lincoln's Inn. Six centuries on, the dinners continue.