 As the Northern situation was still difficult, Edmund was given joint command of the Scottish Border with Lancaster, but the two fell out, and Lancaster was soon after given sole command.It did not take long for Edmund to grow disenchanted with the new regime; one source of contention was the dominant position at court of Mortimer, who has been described as Isabella's lover.In the autumn of 1328, Edmund and his brother Thomas joined Henry of Lancaster in a conspiracy against Isabella and Mortimer.