Both my boys have been pretty good sleepers but 10 months to about 11 and a half months they both went pear-shaped. After a few weeks, they went back to sleeping through again.

As a last resort for the sleep deprivation, I would take DS for a walk in the pram. He would be asleep by the end of the block. I would find a park and sit down and just let him sleep. Once he had one sleep it seemed easier to get him to go back down later.

Another option that worked for us was the car. Thankfully we live in a beautiful area and would just drive for an hour or more. Always worked (even at 3am when I was ready to kill anyone as I hadn't got to bed yet!! DH would go for the drive then and let me sleep).