How A Failed Royal Pardon Became A Limit To A President's Power Of Pardon

The English word "impeach" is derived from the Latin preposition in, meaning in, on or into, and noun pedica, meaning a shackle or snare.  The earliest recorded case of impeachment by the English House of Commons was in 1376 during the reign of Edward III.  The accused was William Latimer, the 4th Baron Latimer.  The practice continued for the next four reigns, but then died out until James I took the throne in 1603.   The revival of impeachment led to the question of whether a royal pardon would bar impeachment.  As recounted in this post from December 2019, the question was answered in the reign of Charles II, The Merry Monarch:

"In 1678, the Commons impeached Thomas Osborne, the Earl of Danby, despite a royal pardon.  The Commons' action was eventually enshrined in statute: 'no Pardon under the Great Seal of England be pleadable to an Impeachment by the Commons in Parliament'.   Act of Settlement (1700), Section III.  The California Constitution includes a similar limitation on the power of the Governor to pardon impeachments:

'Subject to application procedures provided by statute, the Governor, on conditions the Governor deems proper, may grant a reprieve, pardon, and commutation, after sentence, except in case of impeachment.'

Cal. Const. Art. V, § 8(a)."

The same pardon exception can be found in Article II, Section 2 of the United States Constitution:

"The President . . . shall have Power to grant Reprieves and Pardons for Offences against the United States, except in Cases of Impeachment."

Sometimes impeachments do not end badly for the accused.   Although imprisoned, Baron Latimer was eventually freed on bail and in 1376 he was restored to greater favor than ever.  Thomas Osborne was confined to the Tower of London but was later released.  On June 30, 1688, he became one of the so-called 'Immortal Seven' who invited William of Orange and Mary II to depose James II in the 'Glorious revolution'. "