Tehran Iran, Silk Road

Before Tehran became the bustling capital of Iran in the late 18th century, the area was part of a much older historical landscape, deeply intertwined with the Silk Road. The southeast region where Tehran sits today was home to the ancient city of Rhages (modern-day Ray). It was an important city through various Persian empires for several centuries, lasting from the Achaemenid Empire (6th–4th century BCE) to the Sassanian period (3rd–7th century CE).

However, after being conquered by Muslim empires in the 7th century, Ray became part of the Islamic world and maintained its importance for the next six centuries until the devastating Mongol invasion in the 13th century, which led to its near destruction. Following this, the city was abandoned, and its inhabitants moved to Tehran, which began to grow in prominence. As a result, Ray's influence steadily declined while Tehran expanded and eventually absorbed it within its boundaries.

One of the last remaining landmarks from Ray's once-glorious past is the Toghrol Tower, a 12th-century monument standing 66ft (20m) tall. Constructed from brick, the tower has a polygonal design with 24 angles, which is believed to provide stability during earthquakes, although its conical dome has long toppled after a seismic event. Traditionally believed to be the tomb of Tughril Beg, the founder of the Seljuk Empire, the exact identity of the buried person remains a subject of debate among historians. It is also said the tower guided Silk Road travellers during foggy nights by lighting a fire, much like a lighthouse, to help them navigate their way to Ray. 

A notable figure in Ray's history is Abū Bakr al-Rāzī, a Persian physician and philosopher, often regarded as the father of paediatrics and an influential figure in obstetrics and ophthalmology. Born in the city in the 9th century, he significantly contributed to medicine. He was the first to distinguish smallpox from measles and propose effective treatments for smallpox. His discoveries in medicine and his work in logic and astronomy were recorded in over 200 manuscripts, many of which were later translated. His 23-volume medical textbook al-Kitab al-Hawi (Comprehensive Book on Medicine) was incorporated into the curriculum at Western universities.

Ray's decline and abandonment opened the door to Tehran's emergence, which benefited from its location on fertile plains. Tehran remained a small village until the Qajar ruler, Agha Mohammad Khan, appointed it the capital in 1786, ushering in a new modern era.