Q:

Select n latest rows between two SQLite tables

I have two tables A and B in an SQLite database.  Table A looks like this:
|  id  |  name         |  description  |  created     |
|------|---------------|---------------|--------------|
|  1   |  "Something"  |  "Something"  |  1466266963  |
|  2   |  "Something"  |  "Something"  |  1466266965  |
|  3   |  "Something"  |  "Something"  |  1466266967  |
|  4   |  "Something"  |  "Something"  |  1466266969  |
|  5   |  "Something"  |  "Something"  |  1466266971  |
|  6   |  "Something"  |  "Something"  |  1466266975  |

And the table B is like that:
|  id  |  title        |  content      |  created     |
|------|---------------|---------------|--------------|
|  1   |  "Something"  |  "Something"  |  1466266951  |
|  2   |  "Something"  |  "Something"  |  1466266953  |
|  3   |  "Something"  |  "Something"  |  1466266954  |
|  4   |  "Something"  |  "Something"  |  1466266956  |
|  5   |  "Something"  |  "Something"  |  1466266957  |
|  6   |  "Something"  |  "Something"  |  1466266978  |

And I want to get the 4 oldest between the two tables. 
So in this example I would get something like that:
|  id  |  title        |  name         |  content      |  description  |  created     |
|------|---------------|---------------|---------------|---------------|--------------|
|  6   |  "Something"  |               |  "Something"  |               |  1466266975  |
|  6   |               |  "Something"  |               |  "Something"  |  1466266975  |
|  5   |               |  "Something"  |               |  "Something"  |  1466266975  |
|  4   |               |  "Something"  |               |  "Something"  |  1466266975  |

I tried SELECT A.*, B.* FROM A, B ORDER BY created DESC LIMIT 4 but I get an empty result (my tables aren't empty though). 
I also looked at JOINs but didn't manage to get anything working. 
Any idea?  Thanks. 

A:

Use union all
select * from(
select * from a
union all
select * from b
) t
order by created DESC LIMIT 4

