The rich man in his castle, The poor man at his gate, God made them, high or lowly, And ordered their estate.

-Alexander, Cecil Frances
  'All Things Bright and Beautiful'.

Theyare a great tradition†gliding in and out of the corridors of power with the opulent calm of angelfish swimming through an aquarian castle.

-Allen, Henry Southworth
  Of presidential advisers. In the Washington Post, 3  Jan.

He was a braw gallant, And he play'd at the ba'; And the bonnie Earl of Murray Was the flower amang them a'. He was a braw gallant, And he play'd at the glove; And the bonnie Earl of Murray, O he was the Queen's luve. O lang will his lady Look owre the castle Doune, Ere she sees the Earl of Murray Come sounding thro'the toun.

-Ballads
'The Bonnie Earl of Murray'.

His coomb was redder than the fyn coral, And batailled as it were a castle wal; His byle was blak, and as the jeet it shoon; Lyk asure were his legges and his toon; His nayles whitter than the lylye flour, And lyk the burned gold was his colour.

-Chaucer, Geoffrey
  Of Chauntecleer. Canterbury Tales,'The Nun's Priest's Tale', l.2859^64.

A man's house is his castle.

-Coke, Sir Edward
  The Third Part of the Institutes of the Laws of England, ch.73.

   Claustrum sine armario quasi castrum sine armamentario. Ipsum armarium nostrum est armamenturium. A cloister without a library is like a castle without an armoury. For the library is our armoury.

-Geoffrey de Breteuil   fl.12c
c.1165  Letter to Peter Mangot.

   The splendour falls on castle walls And snowy summits old in story: The long light shakes across the lakes, And the wild cataract leaps in glory. Blow, bugle, blow, set the wild echoes flying, Blow, bugle; answer, echoes, dying, dying, dying.

-Tennyson
  The Princess, pt.4, added song, stanza1.

Pale rain over the dwindling harbour And over the sea wet church the size of a snail With its horns through mist and the castle Brown as owls.

-Thomas, Dylan Marlais
  'Poem in October'.