The Black Acts were laws passed by Parliament in 1584 which condemned Presbyteries , confirmed the power of the Bishops, said that the king had power over all things (even religion) and gave him the right to decide when General Assemblies.

When the acts were passed, the ministers weren’t happy and some left the country. Until 1592, the church was run as a mixture of Presbyterianism and Episcopalianism

Further Reading:
J. G. Vos, The Scottish Covenanters (Edinburgh, 1998 [1940]), p. 32.
DSCHT: Black Acts
Jenny Wormald, ‘James VI and I (1566–1625)’, Oxford Dictionary of National Biography, Oxford University Press, Sept 2004; online edn, Jan 2008
James Kirk, ‘Melville, Andrew (1545–1622)’, Oxford Dictionary of National Biography, Oxford University Press, 2004