Architecture in the eighteenth and nineteenth centuries was dominated by the phenomenon of revivalism - the practice of using styles from the past.
The two major forms of revivalism were the Gothic Revival and Neo-Classicism, which became locked in a vigorous debate known as the "Battle of the Styles".
In the Georgian era (1714-1830), architecture was dominated by aristocrats. It became fashionable to take the "Grand Tour" of Italy and Greece. They visited the major cultural sites: the monuments of ancient Greece and Rome, and the cities of the Italian Renaissance.
In the eighteenth century architects determined to get back to the origins of western architecture. They began to study the monuments of ancient Greece and Rome. The Parthenon in Athens was built in the 5th century BC [Fig. 1]. This is the greatest monument of ancient Greece. Neo-Classicism was based on the revival of Greek and Roman models.

Fig. 1 The Parthenon, Athens
Euston Station in London originally had a massive Doric archway based on the form of a Greek Temple [Fig. 2]. This was demolished in the 1950s.

Fig. 2 Euston Station, London
One of the leading figures was Alexander Thompson, a Glasgow architect who was known as "Greek" Thompson. He designed the Presbyterian church in Caledonia Road (1856) [Fig. 3]. This emphasises the severity of the Greek style, but it is also very original. Obviously the Greeks did not build churches, so Thomson has had to adapt the form.

Fig. 3 Presbyterian Church, Glasgow
The Greek Revival had an impact in Newcastle. In 1812, the Literary and Philosophical Society built their headquarters in the severe Greek style [Fig.4]. It was suitable for an institution dedicated to intellectual pursuits. This was designed by John and Benjamin Green, who also designed Penshaw Monument in County Durham (1844). This is a replica of the Temple of Hephaestus in Athens, and it's dramatically sited on a hill [Fig. 5].

Fig. 4 Literary and Philosophical Society, Newcastle

Fig. 5 Penshaw Monument
In the 1830s, Newcastle was redeveloped by Richard Grainger. He created a central core of Neo-Classical buildings, which is almost unique in England. Grey Street, Grainger Street and Clayton Street were all built at this time. The centrepiece is Grey's Monument, designed in 1838 by Benjamin Green. It's a single Classical column with a statue on top.

Fig. 6 Grey's Monument, Newcastle
By the 19th century virtually all public buildings in Britain were in the Classical style, which was felt to possess the requisite strength and dignity.