Lady Margaret Beaufort Coat-of-Arms - St Andrew's Street, Cambridge, UK - Coats of Arms on Waymarking.com

Wikipedia in an article about St John's College tells us about the shield and arms:

St John's College and Christ's College, Cambridge both bear the arms of the Lady Margaret Beaufort, Countess of Richmond and Derby, mother of Henry VII. These arms are recorded in the College of Arms as being borne by right, and are described as: Quarterly: 1 and 4 azure three fleurs-de-lis gold (France, Modern); 2 and 3 gules three lions passant gardant or (England); all within a border compony silver and azure. In addition, both foundations use the Beaufort crest, an eagle displayed arising out of a coronet of roses and fleurs-de-lis all gold, but their title to this is more doubtful. When displayed in their full achievement, the arms are flanked by mythical yales.

Wikipedia has an article about Christ's College that tells us:

Christ's College is a constituent college of the University of Cambridge. The college includes the Master, the Fellows of the College, and about 450 undergraduate and 170 graduate students. The college was founded by Lady Margaret Beaufort in 1505, its royal charter granted on 1 May of that year, and was the twelfth of the Cambridge colleges to be founded in its current form. It was originally established as God's House in 1437. The college is renowned for educating some of Cambridge's most famous alumni, including Charles Darwin and John Milton.

Within Cambridge, Christ's has a reputation for strong academic performance and tutorial support. It has averaged 1st place on the Tompkins Table from 1980–2006 and third place from 2006 to 2013.

As of 2013, it had an endowment of £138 million, making it one of the wealthier colleges in Cambridge.