Amid his professional career success, Rachmaninoff married Natalia Satina on 12 May 1902 after a three-year engagement. Because they were first cousins, the marriage was forbidden under a Canon law imposed by the Russian Orthodox Church; in addition, Rachmaninoff was not a regular church attendee and avoided confession, two things a priest would have had to confirm that he did in signing a marriage certificate. To circumvent the church's opposition, the couple used their military background and organised a small ceremony in a chapel in a Moscow suburb army barracks with Siloti and the cellist Anatoliy Brandukov as best men. They received the smaller of two houses at the Ivanovka estate as a present and went on a three-month honeymoon across Europe. Upon their return, they settled in Moscow, where they had two daughters, Irina Sergeievna Rachmaninova (1903–1969) and Tatiana Sergeievna Rachmaninova (1907–1961). Rachmaninoff resumed work as a music teacher at St. Catherine's Women's College and the Elizabeth Institute. By February 1903 he had completed his largest piano composition of his career at the time, the "Variations on a Theme of Chopin" (Op. 22). Development on other pieces was disrupted after Natalia, Irina, and he were struck with illness during their summer break at Ivanovka.