Bits of Poems on the Underground, London's subtler relative of Leiben's wall poetry, are archived online here.
The collection includes a 15th Century poem by an anonymous author called 'I shall say what inordinate love is':
I shall say what inordinate love is:
The furiosity and wodness of mind,
An instinguible burning, faulting bliss,
A great hunger, insatiate to find,
A dulcet ill, an evil sweetness blind,
A right wonderful sugared sweet error,
Without labout rest, contrary to kind,
Or without quiet, to have huge labour.