Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

Context: The Battle of the Standard, sometimes called the Battle of Northallerton, in which English forces repelled a Scottish army, took place on 22 August 1138 on Cowton Moor near Northallerton in Yorkshire.
Question: When did Battle of the Standard occur?
22 august 1138