In what year was the modern Lego brick patented?

The modern LEGO brick was patented in 1958.

Earlier LEGO bricks appeared in 1949, but they were hollow and lacked the internal tube structure that gives modern bricks their strong clutch power. LEGO designer Godtfred Kirk Christiansen worked on improving the connection between bricks so models would be more stable and easier to rebuild.

On January 28, 1958, LEGO submitted a Danish patent application for a toy building element using the now-familiar stud-and-tube principle. The patent date is why 1958 is associated with the birth of the modern LEGO brick, even though LEGO had already been producing plastic building bricks for several years.

A common mix-up is choosing 1949, the year LEGO’s early plastic Automatic Binding Bricks were introduced. Another milestone came in 1957, when the three-tube solution was developed. The 1958 patent transformed that earlier experimentation into the basic brick design still used today.