In the Middle Ages, the authority of the City of London Corporation reached beyond the City's ancient defensive walls in several places, known as the Liberties of London. To regulate trade into the City, barriers were erected on the major entrance routes wherever the true boundary was a substantial distance from the nearest ancient gatehouse in the walls. Temple Bar was the most used of these, since traffic between the City of London (England's prime commercial centre) and the Palace of Westminster (the political centre) passed through it. It was located where Fleet Street now meets The Strand, which is outside London's old boundary wall.