He was the eldest son of Rowland Meyrick, bishop of Bangor (Gwynedd), by Katherine, daughter of Owain Barret of Gelliswic.
He thenceforth made Wigmore Castle his chief country residence; his London house was in the parish of St Clement Eastcheap.
[1] In 1596 Meyrick accompanied Essex on the expedition to Cadiz, serving as lieutenant-colonel in Sir Conyers Clifford's regiment, and also acting as commissioner of stores.
In the Earl's disputes with Walter Raleigh in the course of the expedition, Meyrick strongly supported his master, and is credited with embittering the relations between the two leaders.
A month later Essex, once more at liberty, was considering suggestions of rebellion with a view to regaining his hold on the government, and Meyrick entertained in his master's mansion potential supporters.
When in January 1601 Essex had decided on raising an insurrection in the city, Meyrick armed many of his country friends with muskets and invited them to London; and he gave 40 shillings to the actors of the Globe Theatre on condition that they performed, on the day (Saturday, 6 February) before the day fixed for the outbreak, the play of Richard II representing the abdication of an English sovereign on the stage (according to many accounts), or (as has been argued) John Hayward's Henry IV.
Around 1584, Meyrick married Margaret, daughter of Ieuan Lewys of Gladestry, Radnorshire, and widow of John Gwyn of Llanelwedd; she inherited the estates of both her father and first husband.