TL;DR: LEGO started as a wooden toy company in a small Danish workshop during the Great Depression, and it almost went bankrupt twice before a single piece of plastic changed everything. The invention that made LEGO into LEGO, the "clutch power" that lets bricks lock together with a satisfying click, was patented in 1961 by a carpenter's son who had been running the company since his twenties. Original patent prints from that 1961 design are available framed or unframed.
In 1942, the LEGO factory in Billund, Denmark burned to the ground. Ole Kirk Christiansen, the carpenter who had founded the company a decade earlier, had barely recovered from a first fire in 1924 that had destroyed his house and workshop. He rebuilt. Two years after the 1942 fire, a second fire destroyed the factory again. Christiansen rebuilt again. The man was either extraordinarily resilient or unable to imagine doing anything else. Probably both. Out of that cycle of loss and reconstruction came one of the most recognized brand names in the world and a brick that has been produced, with only minor modifications, for over 65 years.
The history of LEGO is built on that same stubbornness. The company survived the Depression, two fires, an ill-timed pivot to plastic, and near-bankruptcy in the 1990s, and emerged from each crisis by making the core product better.
Ole Kirk Christiansen and the Billund Workshop
Ole Kirk Christiansen was born in 1891 in Filskov, a small village in Jutland, Denmark. He trained as a carpenter and joiner, establishing his own workshop in Billund in 1916. For the first fifteen years, the workshop produced general carpentry: furniture, houses, household items. The Depression changed the economics of his business abruptly. Large construction projects dried up, and Christiansen pivoted to smaller items he could sell more quickly: stepladders, ironing boards, and eventually toys.
He began making wooden toys in 1932, a practical decision driven by necessity rather than passion, though the passion came. His toys were simple, sturdy, and well-made: the quality standards of a trained carpenter applied to objects small enough for a child to hold. Christiansen named his company LEGO in 1934, from the Danish phrase "leg godt," meaning "play well." He did not learn until years later that "lego" is also Latin for "I assemble" or "I read." The double meaning seemed appropriate.
The wooden toy business grew steadily through the late 1930s. By the time World War II disrupted European trade, LEGO had a catalog of more than 40 wooden products and a small but loyal retail network within Denmark. The fires, the first in 1942 and the second in 1944, each time destroying the factory, each time were rebuilt. Christiansen was not a man who stopped.
The Plastic Pivot and the Kiddicraft Connection
The postwar period brought new materials and new possibilities. Christiansen purchased an injection-molding machine in 1947, one of the first in Denmark, and began experimenting with plastic. In 1949, LEGO introduced its first plastic building bricks, calling them "Automatic Binding Bricks." They were based partly on a design by Hilary Fisher Page, a British toy inventor who had patented a similar brick concept in 1939 under the Kiddicraft brand. Christiansen had seen Page's bricks and incorporated the stud-and-hollow-base design into the LEGO version.
The plastic bricks were not an immediate commercial success. Danish toy retailers were skeptical; the prevailing view was that plastic was an inferior material compared to wood, suitable only for cheap products. LEGO's wooden toys were respected. The plastic bricks seemed like a step backward. For several years in the early 1950s, Christiansen considered abandoning the plastic brick line entirely. He did not, partly because he believed in the product and partly because his son Godtfred had become increasingly convinced the bricks had unrealized potential.
The breakthrough in perception came slowly, then quickly. The bricks were redesigned several times in the early 1950s, improving the clutch between pieces. In 1954, Godtfred Kirk Christiansen, by then the company's junior managing director, had a conversation with a buyer at a toy trade fair in England who complained that the toy market lacked a genuine system: interconnected toys where each piece worked with every other piece to produce a coherent whole. Godtfred returned to Billund with an idea.
The LEGO System: An Interconnected Toy
The LEGO System in Play, introduced in 1955, was a conceptual leap as much as a product development. The idea was simple but had not been fully realized before: all LEGO bricks would be designed to work together, regardless of when they were purchased, so that a child could combine sets bought years apart into a single creation. The system was modular by design, and modularity required that every brick fit every other brick precisely, consistently, and permanently.
The problem was that the existing bricks did not quite achieve this. The original plastic formulation and mold tolerances meant that bricks connected, but not with the firm, satisfying grip that would make complex constructions possible. Pieces that came apart too easily were not useful for building anything ambitious. The "clutch power" of the brick, the firmness and reliability of the connection between studs and the inside of hollow bases, needed to be improved substantially.
This was not a minor manufacturing tweak. Getting consistent clutch power required understanding the exact dimensions of the stud and hollow base, the right plastic formulation, and the manufacturing tolerances that would produce a connection firm enough to stay together under play conditions but loose enough to be separated by a child's fingers. LEGO's engineering team worked on the problem through the late 1950s, producing extensive testing data on brick dimensions and force measurements.
Godtfred Christiansen and the 1961 Patent
Ole Kirk Christiansen died in March 1958, one month after LEGO had filed the foundational patent for the brick's clutch-power design. His son Godtfred had been effectively running the company for several years by that point and had been the driving force behind both the system concept and the engineering work that made it functional. Godtfred was 34 when his father died. He had been working at LEGO since he was twelve.
In 1961, Godtfred Christiansen of Billund, Denmark filed a patent for the LEGO clutch power system: the specific engineering of how the brick's hollow tube interacted with the studs of the brick below to create a firm, reversible connection. The patent covered the geometry that enabled bricks to be fastened together securely enough for ambitious construction while remaining separable by hand. This was the technical specification of what made LEGO bricks different from imitators who could copy the shape but could not easily replicate the precise tolerances.
The clutch power patent was one of over 50 designs that Godtfred Christiansen patented for LEGO across his career. It represented the moment the company formalized the engineering insight that had been in development for nearly a decade: that the connection between bricks was not incidental to the toy but was, in fact, the product. Everything else, the sets, the themes, the minifigures, the licensed properties, built on top of that foundational click.
Minifigures, Licensed Sets, and Global Expansion
Under Godtfred's leadership through the 1960s and 1970s, LEGO expanded in two directions simultaneously. The product line grew in complexity and theme, introducing wheels and axles, which made vehicle construction possible, and later the first Duplo bricks in 1969, designed for younger children with larger hands.
The minifigure arrived in 1978, one of the most consequential product decisions in LEGO's history. The small yellow figures with movable arms, legs, and heads gave sets a human scale and made narrative play possible. Children could build a house and then inhabit it; they could construct a spaceship and crew it. The minifigure transformed LEGO from a construction toy into a world-building toy.
Licensed sets, beginning with the Space theme in 1978 and followed by Castle and Town, and then in later decades by Star Wars (1999), Harry Potter (2001), and dozens of other franchises, made LEGO into a cultural touchstone rather than just a toy. The company came close to bankruptcy in 2003 and 2004, the result of over-expansion and product proliferation, and recovered through a return to core product quality and strategic focus. Today LEGO produces over 900 sets per year and employs more than 25,000 people globally.
The brick itself has changed very little since 1958. The dimensions specified in the clutch power work of the late 1950s remain the standard. A brick manufactured today will connect with a brick manufactured 60 years ago. That consistency, the result of the engineering precision Godtfred Christiansen patented in 1961, is what makes LEGO systemically different from almost every other toy on the market.
Shop LEGO Patent Art Prints
LEGO Clutch Power (1961), Godtfred Christiansen
The 1961 patent drawing shows the geometry that made LEGO bricks snap together with the satisfying click recognized by children and adults in over 140 countries. Godtfred Christiansen's engineering specification, shown here in the formal language of the U.S. Patent Office, is the reason a brick made today fits a brick made in the 1960s. This print works equally well in a child's bedroom, a playroom, or an adult space where LEGO holds a place of nostalgia. Clean lines, immediately recognizable subject, and a genuine piece of design history.
Best for: LEGO fans, parents, anyone who built as a child and still remembers the click
Frequently Asked Questions
Who invented LEGO?
LEGO was founded by Ole Kirk Christiansen, a Danish carpenter from Billund, Denmark. He established the company in 1932, initially making wooden toys, and pivoted to plastic building bricks in 1949. His son Godtfred Kirk Christiansen took over the company in 1958 and was responsible for the system concept and the engineering improvements that made LEGO into the globally recognized brand it is today.
What does LEGO mean?
LEGO comes from the Danish phrase "leg godt," meaning "play well." Ole Kirk Christiansen coined the name in 1934, two years after founding the company. It was only later discovered that "lego" is also Latin for "I assemble" or "I read," a coincidence Christiansen found fitting. The company operates under the principle that play is essential to development, a philosophy embedded in the brand name from the beginning.
When was the LEGO brick patented?
The foundational patent for the LEGO brick's clutch power was filed in 1958, the same year Ole Kirk Christiansen died. His son Godtfred followed with additional patent filings including a 1961 patent specifically covering the clutch power system: the engineering of how the brick's hollow tube and studs interact to create a firm, reversible connection. Godtfred Christiansen filed over 50 LEGO-related patents across his career.
Why do LEGO bricks from the 1960s still work with new sets?
LEGO maintains strict manufacturing tolerances based on the dimensional specifications developed in the late 1950s and formalized in the 1958 and 1961 patents. The stud diameter, hollow base dimensions, and clutch force have remained consistent for over 65 years. This backward compatibility is an intentional engineering commitment: it is part of what LEGO means to call all its bricks a "system."
What was the LEGO clutch power patent?
The clutch power patent, filed by Godtfred Christiansen in 1961, covered the specific geometry of how LEGO bricks connect. The "clutch" refers to the grip between the studs on top of one brick and the hollow tubes inside the base of the brick above it. Getting this geometry right required extensive testing of dimensions and plastic formulations. The resulting specification produced a connection firm enough to survive play but loose enough to be separated by a child's fingers: the definitive LEGO click.
Written by Rider Tuff, founder of Timeless Patents. Timeless Patents makes museum-quality patent art prints from original U.S. Patent Office documents, celebrating the inventors behind your favorite toys, tools, and technologies. Every print is available framed or unframed. Shop the full collection →
Cover image: "Pile of light gray LEGO bricks at a LEGO store" by Grendelkhan, licensed under CC BY-SA 4.0, via Wikimedia Commons.
