Less than a year after Lord and Lady Lucan were married, they had their first child. Lady Frances was born on October 24, 1964. Three years later, in September 1967, the couple had a son named George. The Lucan family continued to grow when another daughter, Camilla, was born in June 1970. Shortly after the birth of the children, Lady Lucan developed severe postnatal depression. When she sought treatment for the disorder, the problem was incorrectly diagnosed and treated. Her mental health began to deteriorate slowly. However, the countess was still able to properly care for her children and run the household.
Lord Lucan made some effort to help his wife during her battle with depression. He read up on the subject and tried to persuade her to seek help. He wanted to have her admitted to a psychiatric hospital in 1967 after the birth of George, but his wife did not approve of the medication being offered and refused treatment. Kirk Wilson inInvestigating Murder writes that on another occasion in 1971 Lord Lucan tried again to have his wife admitted to the hospital after he said that she suffered from hallucinations. Once again, she refused and ran from the hospital before making it to the front door.
Between 1971 and 1972, pressure within the marriage began to peak. Lord Lucan became increasingly impatient with his wifes mental illness and sought solace at the card tables. He spent most of his time gambling at a private establishment named the Clermont Club, where he squandered away a large portion of his inheritance.
According to Roy Ranson and Robert Strange in Looking for Lucan: The Final Verdict, Lord Lucans anger and frustrations took a violent course, directed at his wife. Stefanja Sawicka, one of the nannies that previously worked for the Lucans, reported that Lord Lucan would beat his wife. She told of how he had once pushed her down the stairs and tried to strangle the countess. She feared for her life and told Sawicka, Dont be surprised if he kills me one day. She admitted that her husband had violent tendencies and would at times beat her with a stick wrapped in tape.
In 1973, the marriage of Lord and Countess Lucan fell apart. Lord Lucan moved out of the family home and took up residence in a basement apartment on Elizabeth Street. He blamed the breakup on his wifes mental problems. During this time, he would confide in his friends that he was concerned about the well-being of the children. He believed Lady Lucan was mentally incapable of caring for them. He decided to wage a legal battle against his wife. A custody hearing was scheduled for May 1973.
In March 1973, Lord Lucan decided he could wait no longer to be with his children. He followed his children and their nanny in a park and convinced them to go back with him to his apartment on Elizabeth Street to live. For weeks, the children stayed with their father and awaited the custody hearing. Lord Lucan was convinced that if he could prove that his wife was mentally unfit, he could gain permanent custody of the children. He hired a private investigator to follow his wife, hoping to obtain information to secure a future with his children. He would also tape Lady Lucans violent outbursts to demonstrate the severity of his wifes mental disability.
Lord Lucan paid for his wife to receive in-home nursing care for three months. At one point, Lady Lucan had even checked herself into a psychiatric clinic for a brief stint, according to Linda Stratmann. However, although Lady Lucan knew she had a problem with depression, she did not believe that it incapacitated her or made her unable to care for her children. She also believed that her husband was using her depression as a ploy to take the children from her permanently. She intended to fight him for custody.