He summoned (1606) the two Melvilles, Andrew and his nephew James, to London, where Andrew bullied in his own violent style, and was, quite illegally, first imprisoned and then banished to France.
In December 1606 a convention of preachers was persuaded to allow the appointment of "constant Moderators" to keep the presbyteries in order; and then James recognised the convention as a General Assembly.

Suspected ministers were confined to their parishes or locked up in Blackness Castle.

In 1608 a General Assembly was permitted the pleasure of excommunicating Huntly.

In 1610 an Assembly established Episcopacy, and no excommunications not ratified by the Bishop were allowed: the only comfort of the godly was the violent persecution of Catholics, who were nosed out by the "constant Moderators," excommunicated if they refused to conform, confiscated, and banished.
James could succeed in these measures, but his plan for uniting the two kingdoms into one, Great Britain, though supported by the wisdom and eloquence of Bacon, was frustrated by the jealousies of both peoples.
Persons born after James's accession (the _post nati_) were, however, admitted to equal privileges in either kingdom (1608).

In 1610 James had two of his bishops, and Spottiswoode, consecrated by three English bishops, but he did not yet venture to interfere with the forms of Presbyterian public worship.
In 1610 James established two Courts of High Commission (in 1615 united in one Court) to try offences in morals and religion.