From the beginning of 1876, Strindberg and Siri began to meet in secret. Following a successful audition that December, Siri became an actress at the Royal Theatre. They married a year later, on 30 December 1877; Siri was seven months pregnant at the time. Their first child was born prematurely on 21 January 1878 and died two days later. On 9 January 1879, Strindberg was declared bankrupt. In November 1879, his novel "The Red Room" was published. A satire of Stockholm society, it has frequently been described as the first modern Swedish novel. While receiving mixed reviews in Sweden, it was acclaimed in Denmark, where Strindberg was hailed as a genius. As a result of "The Red Room", he had become famous throughout Scandinavia. Edvard Brandes wrote that the novel "makes the reader want to join the fight against hypocrisy and reaction." In his response to Brandes, Strindberg explained that:  Strindberg and Siri's daughter Karin was born on 26 February 1880. Buoyant from the reception of "The Red Room", Strindberg swiftly completed "The Secret of the Guild", an historical drama set in Uppsala at the beginning of the 15th century about the conflict between two masons over the completion of the city cathedral, which opened at the Royal Theatre on 3 May 1880 (his first première in nine years); Siri played Margaretha. That spring he formed a friendship with the painter Carl Larsson. A collected edition of all of Strindberg's previous writings was published under the title "Spring Harvest". From 1881, at the invitation of Edvard Brandes, Strindberg began to contribute articles to the "Morgenbladet", a Copenhagen daily newspaper. In April he began work on "The Swedish People", a four-part cultural history of Sweden written as a series of depictions of ordinary people's lives from the 9th century onwards, which he undertook mainly for financial reasons and which absorbed him for the next year; Larsson provided illustrations. At Strindberg's insistence, Siri resigned from the Royal Theatre in the spring, having become pregnant again. Their second daughter, Greta, was born on 9 June 1881, while they were staying on the island of Kymmendö. That month, a collection of essays from the past ten years, "Studies in Cultural History", was published. Ludvig Josephson (the new artistic director of Stockholm's New Theatre) agreed to stage "Master Olof", eventually opting for the prose version – the five-hour-long production opened on 30 December 1881 under the direction of August Lindberg to favourable reviews.