The Block house was the immediate area outside the City Walls on the east and was part of the Liberties of the City. It was a network of ditches much like Sedgemoor. Even in the 1850's one remained, with its path along, known as 'Withy Walk', now St Paul's Street.
In the Civil War, the City Walls were long and low at this point, for it was only necessary to dam Frog Mill stream to convert the whole area into a morass. At the Battle of Worcester in 1651, some of the Scots horsemen camped in the area- roughly along the present line of the canal as far as Lowesmoor, thus screening the walls and protecting a line of retreat, while Cromwell occupied all the high ground from Ronkswood to Red Hill, but there was little fighting done there.
In 1246, the King gave the Friars permission to have a postern gate in the town wall to give access to their burial ground and the Church. This gate came to be know as Friars Gate. In 1820 a new road was constructed from Friars Gate to the Blockhouse, called Union Street, and it marked a distinct stage in the growth of Worcester on the east, for up to that time the City had been hermetically sealed, as regards ordinary vehicular traffic, by the City Walls, although the old postern Friar's Gate gave limited access to the Blockhouse fields. It allowed the area to be built on, and it fixes the date of the Blockhouse district as a residential area. Most of the fields belonged to the Corporation, subject to lease for 41 years, renewable every 14 years. The district was laid out, according to the times, as a 'garden suburb', and in comparison with the dark and narrow 'courts' within the walls, well deserved the title. In the 1860's it still contained pretty gardens, some large size, and even paddocks, but these gradually fell a prey to the speculative builders, and in the suburb become undistinguished from the crowded areas of the old City.
The principal street, Carden Street, was named after a venerable member of the Corporation, Alderman Thomas Carden, who was a Mayor in 1790. He lived to a great age, and his portrait, which is said to be life-like, hangs in the Guildhall. Hiss son, who lived in Foregate Street, became famous as a surgeon.