Louis Blériot, the man who made the first flight over the English Channel in 1909, also established one of the world's first successful aircraft companies and was instrumental in the success of a second company that played a large role in World War I.

After building several gliders and floatplanes with aviation pioneer Gabriel Voisin, Blériot ended his association with Voisin in 1906 and began to build and fly aircraft of his own design. He decided that the future lay with the monoplane. His first monoplane was the canard (tail-first) Blériot V, which flew briefly before it crashed. The same year, he built the tandem-wing Blériot VI Libellule (Dragonfly), which made several short hops at Issy-les-Moulineaux, near Paris, during the summer of 1907—all at an altitude of less than 40 feet (12 meters).

A Romanian lawyer in Paris, Trajan Vuia, had attempted to build the first tractor-propeller monoplane in 1906. Although unsuccessful, he inspired Blériot to try to build one. His Blériot VII appeared in 1907. It marked a milestone for flight performance and aerodynamics. The plane had low, cantilever wings, a covered fuselage, a rudder, and a large, tail assembly. The two parts of the tail assembly could be moved jointly to act as elevators or independently to act as ailerons. The enclosed Antoinette engine drove a four-blade metal tractor propeller, which was directly connected to the crankshaft. The plane was tested in November and December 1907 at Issy, and made a total of six flights. In two flights, the plane covered more than 1,640 feet (500 meters) at a speed of about 50 miles per hour (80 kilometers per hour).

The fabric-covered Blériot VIII followed. It had an instrument layout, which Blériot patented, that is still the basic layout of the modern aircraft today. The Blériot IX and uncompleted Blériot X pusher biplane followed.

The Blériot XI, of English Channel fame, made its first flight at Issy on January 23, 1909. This plane established the classic formula of the tractor monoplane that remained unchanged until the start of World War I. It incorporated many features taken for granted in later planes: monoplane wings, a tractor propeller directly attached to the crankshaft, a hinged tilting stick and rudder pedal controls, and a covered fuselage.

The plane was first equipped with a 30-horsepower REP engine, which drove a four-bladed metal propeller. During testing, the engine was replaced by a 22/25-horsepower Anzani and a Chauviere two-bladed propeller. Other changes involved the control system: the rudder was enlarged, while the elevons at the outer edge of the tail assembly were made to function only as elevators. Their lateral function was taken over entirely by warping the trailing edges of the wings. The fuselage was built of ash with supporting struts and wire ties, and the shoulder-mounted wing was also wood. The tail assembly consisted of a central rudder and elevators at each end of fixed horizontal tail surfaces. The main landing gear consisted of two large bicycle wheels, connected to a pair of steel tubes braced by wooden beams.

Blériot's Channel crossing ensured him an important place in aviation history. Within weeks, he received more than 100 orders for the Blériot XI. Between 1909 and 1912, nearly every European aviation contest had a Blériot XI among its winners, and the type was flown by most of the leading aviators in Europe. Harriet Quimby, the first woman to fly the English Channel, flew a Blériot XI. By the end of 1913, Blériot had delivered 800 aircraft of the 1,294 aircraft of all types built in France that year.

The Blériot XI was also the first plane sold to the French Army and the first to serve during military operations. Captain Carlo Piazza flew it on October 23, 1911, in the war between Italy and Turkey.

The 1914 model of the Blériot XI was one of the world's first fighters. At the outbreak of World War I, five British squadrons had Blériot XIs. When France mobilized in July 1914, the Aéronautique Militaire purchased 25 Blériot XIs. The Blériot XI-2 could be armed with grenades or fléchettes (small darts). In the first year of the war, it was one of the most widely used observation planes and served with 21 French, British, and Italian squadrons. Five models were developed, and 132 planes were built during the war. By the war's end, Blériot's company could produce 18 planes per day.

Developed soon after the first Blériot XI, the Blériot XII first flew on May 21, 1909, at Issy. It could carry a passenger as well as a pilot and was the first aircraft to carry three people. The plane crashed at Reims on August 29, 1909.

In 1914, Blériot took over as president of the failing aircraft company called Société pour les Appareils Deperussin and renamed it Société Anonyme Pour l'Aviation et ses Derivés, better known as SPAD. SPAD went on to produce a series of aircraft that may have been the best Allied combat aircraft of World War I. The SPAD VII, designed in 1916, featured a single fully synchronized machine gun and a top speed of more than 119 miles per hour. In France alone, 5,600 of these planes were built.

SPAD's chief designer Louis Béchereau went on to create the SPAD XIII, which some consider to be the best Allied aircraft of the war. It incorporated a pair of fully synchronized Vickers machine guns and could fly at 138 miles per hour. More than 8,400 SPAD XIIIs were delivered before the end of the war. France's top aces Rene Fonck, Charles Nungesser, and Georges Guynemer all flew this plane as well as Americans Frank Luke and Eddie Rickenbacker.

After the war ended, Blériot and SPAD merged. During the 1920s and 1930s, the company produced a large number and wide variety of quality aircraft used by several European airlines and nations under both the SPAD and Blériot labels. The SPAD 33 of 1920, a biplane, developed into a family of similar aircraft with seats for four to six passengers that ended with the SPAD 126 in 1929. The most noteworthy of these variants was the SPAD 56, which set an altitude record in 1923 by reaching 26,900 feet (8,200 meters) while carrying a cargo of 550 pounds (250 kilograms). More than 100 of these biplanes were built. Some could cruise at 106 miles per hour (170 kilometres per hour).

The Blériot 115's innovative design had four engines installed in pairs, two on the upper wing and two on the lower. Each had a fuel tank set just above it. The engines could be started in flight and it was claimed that it could take off with only two engines operating. Two of these planes were assigned to the military and in 1925, they crossed the Sahara desert in nineteen days. The Blériot 135 was one of the first four-engine planes designed expressly for civil transport and one of the small planes used exclusively on the Paris-London route. The Blériot 110 was the plane flown by Lucien Bossoutrot and Maurice Rossi when they set a world record for closed-circuit distance flying in February 1931. It was also used for several other long-distance records in the early 1930s.

The Blériot 125 was first flown in 1931. Although it never got beyond the prototype stage, it attracted a great deal of attention at the 12^th Salon de l'Aviation in Paris in November 1930. Its unusual configuration was designed to provide the maximum comfort for its twelve passengers. It had two separate fuselages below the wings. Each fuselage ended in a tail piece supporting the tail unit. The three-man crew was housed in a small central cabin over the wing. One of the two Hispano-Suiza 500-horsepower engines powered a tractor propeller and the other went to a pusher propeller.

Blériot continued to produce military and civil airplanes and seaplanes up to 1935, when his manufacturing business was closed.