By the beginning of the nineteenth century the Old Hall was becoming inadequate for meeting all the demands made upon it; and the membership of the Inn was increasing apace. The foundation stone of the Great Hall (or New Hall) was laid on April 20, 1843; the year and the initials of the architect, Philip Hardwick, can be seen worked into the brickwork, high on the southern face of the hall. In a stately ceremony, Queen Victoria opened the hall on October 30, 1845. An artist's impression of the scene hangs in the lobby at the south end of the hall. In place of a hall measuring 72 by 32 feet, the Inn thereafter had a hall 120 feet long by 45 feet wide, more than double the size, and the largest in any of the Inns. The centenary of the Royal opening of the Great Hall was commemorated when on October 30, 1945, Queen Mary planted a walnut tree in the North Lawn of the Inn.
In common with some other fine trees in the Inn, this perished in the hurricane in October 1987; and the next year Princess Margaret planted a replacement in New Square.
The Great Hall now serves all the normal purposes of a hall in an Inn. During the four dining terms of the year, each 23 days long, it is used for dining, and students of the Inn keep their terms then. In addition, the hall provides lunches for members throughout the year; and the social and professional fellowship that this affords is an important facet of life at the Bar. Because of its size and acoustics, the hall has also been found a desirable venue for choral and orchestral concerts arranged by the Bar Musical Society.
The Old Hall is used today for lectures and a variety of social and other functions. Much of the life of the Inn centres round the Great Hall. It is here, four times a year, that the formal ceremony of calling students of the Inn to the Bar takes place. In the presence of a number of other benchers and of friends and relations of those concerned, the Treasurer says to each student in turn, ''Mr. A. B., by the authority and on behalf of the Masters of the Bench I publish you a barrister of this Honourable Society''. With those simple words the student becomes a barrister, and what may be a distinguished career in the law has begun. New benchers, too, are published in a similar way at lunchtime, when the Hall is full. During the dining terms, there are a number of moots or debates for students, or talks by well-known lawyers.