A circus is an arena for acrobatic exhibitions and animal shows. Usually circular and surrounded by tiers of seats for spectators, a circus may be in the open air but is usually housed in a permanent building or sheltered by a tent. The term circus is also applied to the performance itself and to the troupe of performers. The entertainment offered at a circus generally consists of displays of horsemanship; exhibitions by gymnasts, aerialists, wild-animal trainers, and performing animals; and comic pantomime by clowns. The first modern circus was staged in London in 1768 by Philip Astley, a former sergeant major in the English cavalry, who performed as a trick rider. Beginning with a visit to Paris in 1772, Astley introduced the circus in cities throughout continental Europe and was responsible for establishing permanent circuses in a number of European countries as well as in England.

A circus was first presented in Russia in 1793 at the Winter Palace in Saint Petersburg. By the early 19 th century several permanently based circuses were located in many larger European cities. In addition, small traveling shows moved from town to town in caravans of covered wagons in which the performers lived. The traveling shows were usually simple affairs, featuring a fiddler or two, a juggler, a ropedancer, and a few acrobats. In the early circuses such performers gave their shows in open spaces and took up a collection for pay; later, the performers used an enclosed area and began to charge admission.

By contrast, the permanently-based circuses of Europe staged elaborate shows. In the earlier part of the 19 th century a main feature of the permanent circus program was the presentation of dramas that included displays of horsemanship. The circus was introduced in the United States by John Bill Ricketts, an English equestrian who opened a show in Philadelphia, Pennsylvania, in 1792 and staged subsequent circuses in New York City and Boston, Massachusetts. President George Washington reportedly attended a Ricketts circus and sold the company a horse in 1797. The Ricketts circus remained in existence, with several name changes, through the first decade of the 19 th century.

Some of the outstanding companies in the early history of American circuses were the Mount Pitt circus and the troupes of the American animal tamer Isaac Van Am burgh, the American chemist and inventor Gilbert Spaulding, and the American clown Dan Rice. Throughout the 19 th century the circus evolved in programming and management. Initially, trained horses and equestrian performances dominated circuses, but rope dancing, juggling, acrobatic acts, wild-animal acts, and clowning were all introduced within the first few decades. The flying trapeze, an important part of the modern circus, was not invented until 1859, and the street parade and sideshow did not become standard circus events until later in the 19 th century.

Tents are believed to have come into use in the 1820 s, but it is uncertain whether they appeared first in Europe or in the United States. The huge multi ring circus set up to accommodate thousands of spectators is a peculiarly American development. In 1869 William Cameron Coup organized a show of unprecedented size that gave performances simultaneously in two rings. Coup formed a partnership with the American showman P.

T. Barnum, and in 1871 they opened a huge circus in Brooklyn, New York. This circus was advertised as 'The Greatest Show on Earth.' Ten years later Barnum went into partnership with the American showman James Anthony Bailey, one of the best organizers in the business, and two other impresarios. The new circus, in which Barnum and Bailey eventually became sole partners, was so large that it staged simultaneous shows in three rings.

In 1884 the five Ringling brothers, most notably Charles and John, organized their first circus. In succeeding years the Ringling brothers took over six circus companies, including Barnum and Bailey, which they bought in 1907. In 1929 the Ringling Brothers and Barnum & Bailey Combined Shows, as it was called, bought another combination of companies, the Circus Corporation of America. At the height of its popularity, when it was the largest touring organization in the world, this circus complex used about 300 tents to stage a show and carried its own diesel plants to generate electricity.

After World War II ended in 1945, however, mounting labor costs and freight charges made such large-scale tenting impractical. Thus, in 1956 John Ringling North announced that his Ringling Brothers and Barnum & Bailey Circus would henceforth appear only in permanent buildings. In 1969 the circus began operating as two separate units-the Red and the Blue-each available to play in about 50 arenas during a season lasting about ten and a half months. At the present time, approximately 40 other circuses tour the United States and Canada.

The Canadian company Cirque du Soleil introduced artistic and expressionistic elements into its acrobatic performances. The company toured throughout the world during the late 1980 s and early 1990 s and gained a large popular following, becoming one of the world's leading contemporary circuses.