Is there any theological basis for the eating of lamb at Easter? I'm almost certain that the answer is no and that lamb is eaten mostly because it's available and tasty. However my attempts to Google this have met with limited success. I have found suggestions that the practice originated with the popes towards the end of the first millennium AD, and of course lots of articles suggesting a connection with Passover and with the lamb of God. However I have been unable to find any definitive statements from a reliable source.

I would be interested to if there is any religious significance to the eating of lamb, or whether it's one of those traditions that owe more to pragmatism than theology.

A footnote

Lee asks me to clarify my question. Suppose I was asking why Jews eat lamb at Passover, then the answer would be that it's mandated in the Torah. This would be a nice clear answer that is easily independently checked.

I want to know why Christians eat lamb at Easter, but I am fairly sure there is nothing in the Bible instructing them to do so. So I am anticipating that the answer might be along the lines of:

Because Pope Whoever adopted the practice in 962 and it has been a tradition ever since

or possibly:

There is no clear reason - it has just become popular due to the association of the Lamb of God with Jesus

Lesley mentions it became a tradition in the ninth century, but the linked article is very vague about who adopted the tradition and exactly when. If a more precise origin for the tradition can be identified I would be very interested to know it.

So when I ask about a theological basis I mean was there some occasion when Christians were instructed to eat lamb or when they were encouraged to eat lamb by an example set by some Christian authority? Or has the practice simply emerged without any clear origin?
It seems that the Catholic tradition of eating lamb at Easter was first documented in the 7th century:


  “The oldest prayer for the blessing of lambs can be found in the seventh-century sacramentary (ritual book) of the Benedictine monastery, Bobbio in Italy. Two hundred years later Rome had adopted it, and thereafter the main feature of the Pope's Easter dinner for many centuries was roast lamb.” - Easter Symbols and Food (Catholic Culture)


Eating lamb at this time of the year has religious significance, not only for Christians but also for Jews.  It goes back to the year 1446 B.C. on the night before Moses led his people out of Egypt.   To this day the Passover (Pesach in Hebrew) is the most widely celebrated Jewish festival where a lamb is roasted then eaten.  It is called the Passover because the angel of death passed over the homes of the Israelites who had obeyed God’s commands to kill a lamb and then mark their doorposts and lintels with its blood:


  “Then Moses called all the elders of Israel and said to them, “Go and select lambs for yourselves according to your clans, and kill the Passover lamb. Take a bunch of hyssop and dip it in the blood that is in the basin, and touch the lintel and the two doorposts with the blood that is in the basin. None of you shall go out of the door of his house until the morning. For the Lord will pass through to strike the Egyptians, and when he sees the blood on the lintel and on the two doorposts, the Lord will pass over the door and will not allow the destroyer to enter your houses to strike you. You shall observe this rite as a statute for you and for your sons forever.” (Exodus 12:21–24). 


The theological significance for Christians is that on the night he was betrayed, Jesus and his apostles gathered together in a room in Jerusalem to prepare for the Passover.  As you have mentioned, there is a connection with Passover and Jesus, who is seen by Christians as the Lamb of God who was sacrificed and his blood shed to atone for the sins of the world.  That is the theology behind eating lamb on Nisan 14, which is the night Jesus was betrayed.

In Western countries, Passover is celebrated in early- to mid-April and is always close to Easter since that was the time when Jesus was crucified.  Passover and the story of the exodus have great significance for Christians, as Jesus is our Passover (1 Corinthians 5:7; Revelation 5:12). He was killed at Passover time, and the Last Supper was a Passover meal (Luke 22:7–8).  That is the theology behind the eating of lamb and it is traditional among Catholics and Protestants alike.