When was Imam Saud bin Faisal bin Turki able to enter Riyadh

The answer is: 1288 Hijri.

In the year 1288 AH, Imam Saud bin Al-Faisal was able to enter Riyadh, the capital of the Kingdom of Saudi Arabia. Imam Saud III bin Faisal bin Turki Al Saud was born in Riyadh in 1249 AH, and was known for his generosity. Upon entering the city, Imam Saud left a distinctive mark as he participated in a large number of events. Three years later, in 1291 AH, Imam Saud succeeded in establishing his rule, and became the imam of the second Saudi state.