London's calamity was the opportunity for this little man of mighty intellect. Four days after the fire ceased he laid before the king the sketch of his plan for the restoration of the city. He looked far into the future, and in vision saw a splendid town built on a well-conceived, harmonious plan. He proposed to have Ludgate Hill widen as it approached St. Paul's, where it would divide into two broad streets around the cathedral and leave ample space for its huge mass to be plainly viewed. One of these streets should lead to the Tower and the other to the Royal Exchange, which was to be the centre of the city. Around it should be a great piazza, from which ten streets were to lead, and on the outer edge of this piazza would be situated the Post-Office, the Mint, and other important buildings. "All churchyards, gardens, and trades that use great fires and noisome smells" were to be relegated to the country, and the churches with their spires were to be placed in prominent positions on the main thoroughfares.
All this meant present sacrifice for future good; but the short-sighted and impatient Londoners thought of the crying needs of the present year alone. The architect might implore and weep bitter tears, but all in vain. London must rise again on its old, congested plan, with its crooked alleyways and narrow courts. But, though the ground-plan was discarded, Wren was to make the new city his monument. Besides St. Paul's he built within and without the walls fifty parish churches, thirty-six of the companies' halls, the Custom House, and much besides.
During the last eight years of Milton's life, the destruction of the walls of St. Paul's went on and the new edifice was assuming shape in the mind of its creator. The old walls were blown down by gunpowder explosions and by battering-rams. This took about two years, and the clearing away of rubbish and building the massive foundations, longer still. Several schemes were considered and rejected, and the plan which finally took its present form was not begun until the funeral wreaths were withered upon Milton's grave. Into the history of this mighty structure we may not enter. In 1710 the last stone of the lantern above the dome was laid by Wren's son in the presence of the now aged architect and of all London, which assembled for the proud spectacle. The fair walls, ungrimed by soot and smoke, rose fresh and perfect, a monument to one of the greatest geniuses of all time.