Around 40 times in history the Hajj was suspended or the number of pilgrims was extremely low according to King AbdulAziz Foundation For Research And Archives, and this idea is not as unprecedented as perceived.
•Epidemics/Diseases
•Political turmoil
•Economic turmoil
•Instability of security
•Conflicts
•Activities of bandits and raiders
Some years and events when Hajj was either suspended or interrupted:
Ismail bin Yusuf Al-Alawi known as Al Safak and his forces led a rebellion against the Abbasid Caliphate and massacred thousands of pilgrims who were gathered at the Arafat Mountain near Makkah, forcing the cancellation of the Hajj.
Arguably the most infamous event, when a sect called Qaramitah who considered the Hajj to be a pagan ritual led by Abu Tahir Qaramitani carried out an attack on Makkah during the Hajj season... Continued...
It is said that this year it was cancelled because of the spread of the so-called 'Al-Mashiri' disease in Makkah, and because of it the pilgrims died and their camels died on the way from thirst and only a few of them arrived in Makkah.
Hajj was suspended due to extremely high costs and inflation. For the same reason nobody did Hajj from the East and from Egypt in 419 AH.
Hajj was not performed because of the turmoil and lack of security that befell the Muslims throughout their large state due to the raging conflict between themselves, and for five years before the fall of Jerusalem to the hands of the Crusaders.
Apart from Hijaz no other country performed Hajj for four years due to ongoing conflicts.
Hajj trips stopped during the French Revolution due to insecurity of the routes.
In more recent accounts, a plague coming from India spread causing the deaths of a staggering three quarters of the pilgrims.
The epidemics spread in various years from 1837 AD until 1892 AD with thousands dying daily. In 1871 it struck Madinah. This outbreak known as Cholera spread during the Hajj season, as deaths spiked in Arafat and peaked in Mina.
The Coronavirus pandemic (COVID-19) caused suspension of international pilgrims performing Hajj.