take post

Short definition from Wiktionary

Verb

1. 1
   Used other than figuratively or idiomatically: see take, post. To travel (typically rapidly) by posthorse or post chaise; to arrive and assume a military post.
2. 2
   To travel as quickly as possible by whatever means.
3. 3
   To begin to serve any position, particularly (UK military, historical) to be named a post-captain.
4. 4
   To establish oneself in a defensive or offensive position.