Traditionally, churches seated worshippers in pews. Today that has changed to chairs. Why the furniture switch? Because churches used to only be for worship, and they were reliably packed on Sundays. Today church attendance is down, and they've adapted by turning into flexible-use spaces. It's not easy to move pews out of the way or rearrange them for meetings. But individual stacking chairs make the task much easier, and can be stored in small spaces.

So in 2009 British furniture designer Simon Pengelly was commissioned to design a chair for Chorus, a contract furniture manufacturer. The brief was to design a sturdy, comfortable, lightweight, stackable chair for use in churches. The chair also needed to be offered in a linked version, for customers that still desired pew-like configurations.

The result was the Theo chair, made of a solid oak frame and with a pressed ply seat and back.

The chair is available bare, or with armrests and/or upholstery. It's stackable in either configuration.

A purpose-designed trolley makes them easy to move.

The linked configuration uses clips to attach the chairs.

Impressively, even the linked units can be stacked.

Here's a look at the production process:

Theo hit the market in 2011. Not only was the chair a hit, it was so successful that it spawned an entire furniture company called Theo that produces spin-off pieces.