Thousands of photographs, prints and letters that reveal the private passions and public interests of Queen Victoria’s husband Prince Albert have been published online to mark the 200th anniversary of his birth.

The Royal Collection has digitised 17,500 documents for a new website, the majority publicly available for the first time.

A framed photograph of Queen Victoria and Prince Albert, 1860, by John Jabez Edwin Mayall. Photograph: Royal Collection Trust

Curators hope the project will offer a fresh perspective on Albert’s contribution “as Queen Victoria’s unofficial private secretary” as well as his importance for some of the greatest national projects of his day.

By 2020, the hope is that 23,500 items will be available. They include Albert’s collection of 10,000 photographs that covered just about every genre and theme.

Victoria and Albert’s children Prince Alfred and Princess Beatrice c1859. Photograph: Royal Collection Trust

The website includes personal photographs of the royal family which show the couple’s children as they grew up, as well as images which documented the world around him, for example a rare daguerrotype of the Chartist demonstration on Kennington Common in 1848.

A daguerreotype of the Chartist meeting at Kennington Common. Photograph: Royal Collection Trust

Helen Trompeteler, senior curator of photographs at Royal Collection, said Albert was an important figure in the early history of photographs. “He sincerely believed in photography as an art form at a time when its role in society was being debated,” she said. “He really saw photography’s potential across every aspect of society, from art to historical record to being a tool for arts scholarship.”

There are stacks of fascinating personal correspondence between Albert and Victoria on the website. For example when she became Queen in 1837, he sent a letter of congratulations from Germany which probably didn’t ease any worries she might have had about ascending to the throne.

Princess Helena and Princess Louise, April 1859. Photograph: Royal Collection Trust

“My dearest Cousin, I must write you a few lines to present you with my sincerest felicitations to that great change, which took place with your life. Now you are Queen of the mightiest land of Europe, in your hand lies the happiness of millions.”

Queen Victoria with her four eldest children, 1854, c.1880 copy of original by Roger Fenton. Photograph: Royal Collection Trust

A later note, written in German on the day of their engagement, bursts with passion: “How is it that I have deserved so much love, so much affection? I cannot get used to the reality of all that I see and hear, and have to believe that heaven has sent me an angel whose brightness shall illume my life.”

Queen Victoria kept volumes of reminiscences between 1840 and 1861. Photograph: Royal Collection Trust

There are also letters and journal entries by Victoria available to read, including pages about how Albert would play with their children by wrapping a napkin around their waist and swinging them back and forth under his legs. She includes a little drawing for added effect.

Osborne House was built between for Victoria and Prince Albert as a summer home and rural retreat. Photograph: Eamonn McCabe/The Guardian

The website is one of a number of events and projects marking the 200th anniversary of both Victoria and Albert’s birth. On bank holiday Monday, the date of Albert’s birth, anyone sharing his name – Franz August Karl Albert Emanuel – can have free access to the couple’s Isle of Wight retreat, Osborne. Any of the names, English Heritage stressed, not necessarily all of them.