The trust was created in 1895 when it had just one hundred members, and a years membership cost ten shillings.
The National Trust now look after an impressive 700 miles of coastline, 300 historic houses and more than 600,000 acres of land.
Membership totalled one million in 1981, two million in 1990 and reached three million in 2002.
The trust gave £120 million in support to ‘vital’ conservation projects across the whole of the UK. Around 90 million visits were made to National Trust countryside spots last year alone.
Dame Fiona Reynolds, director general of the National Trust, said: ‘Whether it’s a love for their local place, a passion for anything from surfing to fine art, or simply the joy of spending family time together – there’s clearly a growing hunger for what we have to offer.’
She added: ‘In England you are never more than 40 minutes away from somewhere looked after by the National Trust.
‘From the smallest sculleries and garden grottos to towering castle turrets and the wild expanses of Lake District countryside, the National Trust enables everyone to enjoy these beautiful, intriguing and exciting places forever.’
She said the Trust owed a ‘massive thank you’ to members for their support.
She added: ‘We were set up 116 years ago to look after special places so that they could be enjoyed by all. Clearly that founding aim remains as relevant today as it was then.’