Francis Annesley (I) was the first member of the family to achieve major political prominence. His career was devoted almost exclusively to Irish affairs, as he held a succession of
government offices there from 1606. Important landmarks included his taking a prominent part in the colonization of Ulster in 1608, his appointment as one of the Principal Secretaries of in 1618, and then as Treasurer at War in 1625.
In addition to the above posts, Francis (I) also received many titles. He was knighted in 1616 and made a baronet in 1620. In 1621, he was given the reversion on the title of Viscount
Valentia upon the death of the current holder, Sir Henry Power, but was in addition given the title of Baron Mountnorris in 1628. The Viscountcy at last passed to him in 1642.
In the 1630s, Francis (I) had a serious quarrel with Sir Thomas Wentworth, Earl of Strafford, which resulted in his being sentenced to death, but this sentence was overturned in 1641.
Most of Francis (I)'s property was, unsurprisingly, in Ireland. Deeds concerning his lands there may be found at E6/7 below. See too E6/8/1D, for property in Yorkshire which he also acquired.
The following papers consist largely of family settlements.