The Queen has sent her first-ever tweet - and it has been broadcast on the BT Tower.

The monarch used the handle @BritishMonarchy to open a £15.6 million communications exhibition at the Science Museum.

Normally a plaque is unveiled to herald the launch of a new project, but after touring the attraction the Queen touched a tablet screen to send her message to the world - and the iconic landmark in central London.

The Queen's tweet on the BT Tower

BT is the Lead Principal Sponsor of the new Information Age gallery, which tells the story of how information and communications technologies have developed over the past two centuries, underlining the key role that BT and its predecessors have played. Check out the video above to find out more.

[Related story: Exhibition celebrates 200 years of communications technology]

Today’s tweet is not the first time that BT has been part of a major royal first in telecommunications. In 1958, the Queen made the first long-distance telephone call without the help of an operator.

In 1958, the Queen made the first long-distance telephone call without the help of an operator.

On that occasion, the Queen called the Lord Provost in Edinburgh from Bristol and began with the words: “This is the Queen speaking from Bristol. Good afternoon, my Lord Provost.”

The new Information Age exhibition opens at the Science Museum on Saturday.

200 years of communications technology gallery