One of the most famous short poems of Lord Byron. This sonnet is itself the introduction to a long poem, The Prisoner of Chillon, published in 1816. Both concern a patriot and scholar of the early Genevan Republic, one François de Bonnivard (1496-c.1570), who opposed the Duke of Savoy and was imprisoned for two years from 1519 and for seven years from 1530, at Chillon.

Byron in his notes describes the castle at Chillon, an impressive fortress on Lake Geneva, and which he knew from visits. In the dungeon were massy pillars to which Bonnivard was chained, and the path he wore around it was visible still in Byron's day.

Eternal Spirit of the chainless Mind!
Brightest in dungeons, Liberty! thou art,
For there thy habitation is the heart--
The heart which love of thee alone can bind;
And when thy sons to fetters are consign'd--
To fetters, and the damp vault's dayless gloom,
Their country conquers with their martyrdom,
And Freedom's fame finds wings on every wind.
Chillon! thy prison is a holy place,
And thy sad floor an altar--for 'twas trod,
Until his very steps have left a trace
Worn, as if thy cold pavement were a sod,
By Bonnivard! May none those marks efface!
For they appeal from tyranny to God.