Most people familiar with the phrase “warrior monks” probably associate it with Asia. Specifically they would be most likely to think of either Japanese “sohei” or Shaolin monks, neither of which actually fit the phrase all that well.
Why? Because the sohei of Japan were really monks in name only. The large and very powerful Tendai Buddhist temples would hire professional warriors- men who would have been called samurai in any other context- in order to help them throw their weight around in the power politics of that era. These men would shave their heads and throw monkish robes on over their armor, but nobody expected them to really think like monks or live like monks.
Similarly, the Shaolin Temple was a major land-holder, so it maintained an armed militia to protect its property and its political interests. It also encouraged large numbers of itinerant martial artists to stay at subsidiary shrines in the vicinity of the temple, just so there would be a lot of trained fighters around in case of trouble. Because the Chinese imperial government was sometimes not strong enough to ensure national security, it would ask the Shaolin Temple to lend it some troops every now and then. These men were “monks” in a sense, in that they were attached to the temple and were under some sort of religious vow. But they were primarily armed security guards employed by the temple, not true monastic contemplatives.
Europe, however, had a tradition of knights who were truly both warriors and monks. The Hospitallers, the Templars, the Teutonic Knights and other lesser orders were highly disciplined religious organizations as well as military organizations. The knights in these orders were actually expected to live the full monastic lifestyle of poverty, chastity and obedience- although they unquestionably became wealthy and corrupt over time.