Subject: Re: 50,000 US troops in mid-east now
The First Crusade - in reaction to Islamic conquest of the Holy Lands and the plea for help from the Byzantines (the Eastern part of the Roman Empire) - resulted in the recapture of Jerusalem.

One can debate the word "successful", but the First Crusade's stated goal was to recapture Jerusalem, and it did, holding on to it for ~90 years.

Salladin recaptured and we’re still dealing with the blowback.