On 19 January 1644 , a Scottish army under the Earl of Leven invaded Northumberland .
Late in 1643 , Parliament signed a treaty , the Solemn League and Covenant , with Scotland .
On 19 January 1644 , a Scotland army under the Earl of Leven invaded Northumberland .
Late in 1643 , Parliament signed a treaty , the Solemn League and Covenant , with Scotland .